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1. general description the saf784x is a single-chip solution cd audio decoder with on-chip mp3 and wma decoding, digital servo, audio dac, sample-rate converter, preampli?er, laser driver and integrated arm7tdmi-s microprocessor. the device contains all of the required rom and ram, including an internal re-programmable flash rom, and is targeted at low-cost compressed audio cd applications. the design is a one-chip cd audio decoder ic, with additions to allow low-cost system implementation of mp3 and wma decoding. 2. features 2.1 features n channel decoder and digital servo n 32-bit embedded arm7 risc microprocessor supporting both 32-bit and 16-bit (thumb) instruction sets n maximum arm operating frequency of 76 mhz, equivalent to 68 mips n decoding of compressed audio stream (mp3/wma) on arm7 core n all memories required for mp3/wma decoding embedded on chip: combination of 130 kb mask-programmed internal program rom (to reduce wait-states on high-speed code, e.g. decompression algorithms), 42 kb boot rom, 64 kb of internal re-programmable flash rom (for simple re-programming of application code) 110 kb internal sram n programmable clock frequency for arm microprocessor - allowing users to trade-off power consumption and processing power depending on requirements n block decoder hardware to perform c3 error correction n sample-rate converter circuit to convert compressed audio sample rates (in the range 8 khz to 48 khz) to an output rate of 44.1 khz n microprocessor access to digital representations of the diode input signals from the optical pickup; the microprocessor can also generate the servo output signals ra, fo, sl, allowing the possibility of additional servo algorithms in software n programmable pdm outputs (effectively sine and cosine) to allow use of stepper motor for sledge mechanism n microprocessor access to audio streams, both from the internal cd decoder and an external stereo auxiliary input (e.g. an analog source from a tuner, converted to digital via on-chip adcs) to allow audio processing algorithms in the arm microprocessor, e.g. bass boost, volume control n four general-purpose analog inputs (a_in1 to a_in4) allowing the arm microprocessor access to other external analog signals, e.g. low-cost keypad, temperature sensor, via on-chip adcs saf784x one chip cd audio device with integrated mp3/wma decoder rev. 02 9 may 2008 product data sheet
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 2 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder n two additional analog audio inputs (aux_l, aux_r) to allow the arm microprocessor access to external audio signals (e.g. tuner); allows audio algorithms (e.g. bass boost) to be performed on external audio signals n real-time clock operated from separate 32 khz crystal; allows low-power standby mode with real-time clock still operational n watchdog timer n i 2 s-bus, s/pdif, subcode (v4) and subcode sync outputs n 32 gpios n two standard uart channels n two external interrupt pins n i 2 c-bus interface con?gurable for master or slave modes, supporting 100 kbit/s and 400 kbit/s standards n slave i 2 s-bus mode, in which the channel decoder can synchronize the cd playback speed to an i 2 s-bus clock input n integrated digital hf/mirror detector with measurement of minimum and maximum peak values, amplitude and offset n integrated cd-text decoder n up to 6 decode speed, clv or cav modes n lqfp144 package with 0.5 mm pin pitch n separate left and right channel digital silence detection available on kill pins n digital silence detection available on loopback data from external source as well as internal data n filterless pseudo bit stream audio dac with minimal external components n stereo line outputs for audio dac n loopback mode allowing the use of integrated dac with external i 2 s-bus/eiaj sources n compatible with voltage mode mechanisms n on-chip buffering and ?ltering of the diode signals from the mechanism in order to optimize the signals for the decoder and servo parts n lf (servo) signals converted to digital representations by sigma-delta adcs shared between pairs of channels to minimize dc offset between channels n hf part summed from signals d1 to d4 and converted to digital signals by hf 6-bit adc n selectable dc offset cancellation of quiescent mechanism voltages and dark currents, digitally controlled; additional ?ne dc-offset cancellation in digital domain n eye pattern monitor system to observe selectable points within the analog pre-amp n current and average jitter values available via registers n on-chip laser power control, up to maximum currents of 120 ma n laser on-off control, including soft-start control - zero-to-nominal output power in 1ms n monitor control and feedback circuit to maintain nominal output power throughout laser life n con?gured for nsub (n-substrate) monitor diode n jtag interface for device access and arm code development (compatible with arm multi-ice) n all digital input pins 5 v tolerant n low-latency static memory interface to access a maximum of two 2 mb memory
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 3 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder n this product has been quali?ed in accordance with aec-q100 2.2 formats reads the following cd-decode formats n cd-r n cd-rw n cd-da ( cd red book; iec 60908 ) n cd-rom (mode 1 and mode 2) n cd-mp3 n cd-wma n video cd n sacd (cd layer only) n support 80 minute to 100 minute cd playback n multi-session discs 3. ordering information table 1. ordering information type number package name description version saf7846hl lqfp144 plastic low pro?le quad ?at package; 144 leads; body 20 20 1.4 mm sot486-1 saf7847hl
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 4 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 4. block diagram fig 1. saf784x top level block diagram 001aag353 channel decoder digital decoder parallel data interface channel clock control motor control ebu interface register interface i 2 s-bus output block decoder audio processor parallel input and output interfaces block buffer memory c3 erco ahb interface ahb interface programmable rom (130 kb) boot rom (42 kb) flash (64 kb) smiu ahb interface ahb registers ram (110 kb) clock control multi-layer ahb sub-system interrupt controller ahb interface segmentation manager dma controller arm7 cpu timer ( 2) uart ( 2) i 2 c-bus ebu buffer vpb sub-system src gpio watchdog timer real-time clock ahb-to-vpb register interface general purpose adc processor flexi servo interface audio dac line outputs analog laser driver clock analog pll general purpose adcs lf analog adcs hf adc sledge stepper motor driver digital servo servo register interface ahb address decoder
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 5 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 5. pinning information 5.1 pinning 5.2 pin description fig 2. saf784x pinning diagram saf784x 108 37 72 144 109 73 1 36 001aag352 table 2. pin description all digital inputs and bidirectional pins are 5 v tolerant. symbol pin type [1] description sl_sin 1 o sledge actuator/stepper motor pdm output (sine) cos/gpio31 2 b stepper motor pdm output (cosine)/general purpose i/o 31 lpower 3 p laser power supply laser 4 p laser diode drive monitor 5 ai laser monitor diode input vssa1 6 p analog ground 1 hf_mon 7 aio hf monitor output signal vdda1 8 p analog supply voltage 1 d1 9 ai central diode signal voltage input d2 10 ai central diode signal voltage input d3 11 ai central diode signal voltage input d4 12 ai central diode signal voltage input r1 13 ai satellite diode signal voltage input r2 14 ai satellite diode signal voltage input aux_l 15 ai auxiliary audio left signal input aux_r 16 ai auxiliary audio right signal input vdda2 17 p analog supply voltage 2 opu_ref_out 18 ao opu reference voltage vssa2 19 p analog ground 2 oscout 20 ao crystal or resonator output oscin 21 ai crystal or resonator input vdda3 22 p analog supply voltage 3
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 6 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder dac_lp 23 ao audio dac left channel differential output (positive) dac_ln 24 ao audio dac left channel differential output (negative) dac_vref 25 aio audio dac decoupling point (10 m f/100 nf to ground) dac_rn 26 ao audio dac right channel differential output (negative) dac_rp 27 ao audio dac right channel differential output (positive) dac_fgnd 28 p audio dac ?oating ground vssa3 29 p analog ground 3 osc_32k_in 30 ao 32 khz crystal input osc_32k_out 31 ao 32 khz crystal output vddd1 32 p digital core supply voltage 1 a_in1/gpio0 33 aib analog input 1/general purpose i/o 0 a_in2/gpio1 34 aib analog input 2/general purpose i/o 1 a_in3/gpio2 35 aib analog input 3/general purpose i/o 2 a_in4/gpio3 36 aib analog input 4/general purpose i/o 3 vssd1 37 p digital core ground 1 tx/gpio4 38 b uart transmit/general purpose i/o 4 rx/gpio5 39 b uart receive/general purpose i/o 5 tx2/gpio6 40 b uart2 transmit/general purpose i/o 6 dm_addr_0 41 o external memory address bit 0 rx2/gpio7 42 b uart2 receive/general purpose i/o 7 dm_addr_1 43 o external memory address bit 1 sda 44 b micro interface data i/o line (open-drain output) dm_addr_2 45 o external memory address bit 2 scl 46 b microprocessor interface clock line dm_addr_3 47 o external memory address bit 3 lkill 48 o kill output for left channel (con?gurable as open-drain) dm_addr_4 49 o external memory address bit 4 rkill 50 o kill output for right channel (con?gurable as open-drain) vssp1 51 p digital ground 1 to periphery (pads) dobm 52 o bi-phase mark output (no external buffer required) vddp1 53 p digital supply voltage 1 to periphery (pads) dm_addr_5 54 o external memory address bit 5 int2/gpio8 55 b external interrupt 2/general purpose i/o 8 dm_addr_6 56 o external memory address bit 6 gpio9 57 b general purpose i/o 9 dm_addr_7 58 o external memory address bit 7 gpio10 59 b general purpose i/o 10 dm_addr_8 60 o external memory address bit 8 gpio11 61 b general purpose i/o 11 dm_addr_9 62 o external memory address bit 9 table 2. pin description continued all digital inputs and bidirectional pins are 5 v tolerant. symbol pin type [1] description
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 7 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder gpio12 63 b general purpose i/o 12 dm_addr_10 64 o external memory address bit 10 gpio13 65 b general purpose i/o 13 dm_addr_11 66 o external memory address bit 11 gpio14 67 b general purpose i/o 14 dm_addr_12 68 o external memory address bit 12 gpio15 69 b general purpose i/o 15 dm_addr_13 70 o external memory address bit 13 sdi/gpio16 71 b serial data input (loopback)/general purpose i/o 16 dm_addr_14 72 o external memory address bit 14 wlci/gpio17 73 b serial word clock input (loopback)/general purpose i/o 17 dm_addr_15 74 o external memory address bit 15 scli/gpio18 75 b serial bit clock input (loopback)/general purpose i/o 18 vssd2 76 p digital core ground 2 vddd2 77 p digital core supply voltage 2 dm_addr_16 78 o external memory address bit 16 t1/gpio19 79 b tacho input 1 (for spindle motor sensor)/general purpose i/o 19 dm_addr_17 80 o external memory address bit 17 t2/gpio20 81 b tacho input 2 (for spindle motor sensor)/general purpose i/o 20 dm_addr_18 82 o external memory address bit 18 t3/gpio21 83 b tacho input 3 (for spindle motor sensor)/general purpose i/o 21 dm_addr_19 84 o external memory address bit 19 pwm1/cap1/gpio22 85 b timer pwm output 1/capture input 1/general purpose i/o 22 dm_addr_20 86 o external memory address bit 20 pwm2/cap2/gpio23 87 b timer pwm output 2/capture input 2/general purpose i/o 23 dm_bls_0 88 o external ram lower-byte lane select (lower 8-bits) pwm3/cap3/gpio24 89 b timer pwm output 3/capture input 3/general purpose i/o 24 dm_bls_1 90 o external ram upper byte lane select (upper 8-bits) pwm4/cap4/gpio25 91 b timer pwm output 4/capture input 4/general purpose i/o 25 dm_we 92 o external memory right control meas/gpio26 93 b channel decoder telemetry output/general purpose i/o 26 dm_oe 94 o external memory output enable cflg/gpio27 95 b channel decoder correction statistics/general purpose i/o 27 dm_ce_0 96 o external memory chip-select bank 0 cl1/gpio28 97 b clock output for sampling channel decoder telemetry outputs/general purpose i/o 28 gpio29 98 b general purpose i/o 29 vssp2 99 p digital ground 2 to periphery (pads) reset 100 iuh power-on reset (active low) vddp2 101 p digital supply voltage 2 to periphery (pads) table 2. pin description continued all digital inputs and bidirectional pins are 5 v tolerant. symbol pin type [1] description
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 8 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder dm_ce_1 102 o external memory chip-select bank 1 int1 103 iuh external interrupt 1 dm_data_0 104 b external memory data input/output bit 0 vssd3 105 p digital core ground 3 vddd3 106 p digital core supply voltage 3 ef 107 o c2 error ?ag dm_data_1 108 b external memory data input/output bit 1 data 109 o serial data output dm_data_2 110 b external memory data input/output bit 2 wclk 111 o word clock output dm_data_3 112 b external memory data input/output bit 3 sclk 113 o serial clock output dm_data_4 114 b external memory data input/output bit 4 sync 115 o efm frame synchronization dm_data_5 116 b external memory data input/output bit 5 v4/cl16 117 b versatile pin 4/clock output 16.9344 mhz dm_data_6 118 b external memory data input/output bit 6 tdi 119 iu jtag1/2 test data input dm_data_7 120 b external memory data input/output bit 7 tms 121 iu jtag1/2 test mode select dm_data_8 122 b external memory data input/output bit 8 tck 123 idh jtag1/2 test clock dm_data_9 124 b external memory data input/output bit 9 trst 125 iu jtag1/2 asynchronous reset (active low) dm_data_10 126 b external memory data input/output bit 10 tdo 127 o jtag1/2 test data output dm_data_11 128 b external memory data input/output bit 11 arm_jtag_sel 129 i select arm jtag (active high) or general jtag (active low) dm_data_12 130 b external memory data input/output bit 12 rtck/gpio30 131 b jtag clock output/general purpose i/o 30 dm_data_13 132 b external memory data input/output bit 13 dev_rom 133 id development rom select (low = internal rom) dm_data_14 134 b external memory data input/output bit 14 vssd4 135 p digital core ground 4 vddd4 136 p digital core supply 4 dm_data_15 137 b external memory data input/output bit 15 moto1 138 o motor output 1 moto2 139 o motor output 2 vssp3 140 p digital ground 3 to periphery (pads) vddp3 141 p digital supply voltage 3 to periphery (pads) table 2. pin description continued all digital inputs and bidirectional pins are 5 v tolerant. symbol pin type [1] description
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 9 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder [1] see t ab le 3 for pin type de?nition. 6. functional description 6.1 analog data acquisition the input signals from the opu photodiodes contain information used in the servo loops and the high frequency data from which the audio samples are reconstructed. the saf784x contains all the necessary circuitry to process the photodiode signals directly and hence removes the need for a separate external diode signal preampli?er. 6.1.1 lf acquisition the lf signal path acquires the photodiode voltage signals and converts them into 4 mhz pulse-density modulated digital data streams. these streams are processed within the digital servo to control the focus, radial and sledge loops. the servo processing makes use of the difference calculations d1 - d2, d3 - d4 and r1 - r2. ideally these differences should be zero when the quantities d1 to r2 are equal due to the laser illumination. however in a practical system, errors reduce the accuracy of the signal processing. two main forms of errors exist - dc offsets and relative gain mismatch between the difference channels. the dc offsets are minimized in the saf784x by dc-offset compensation circuitry which allows the dc present in the pulse density modulation (pdm) streams to be measured when the laser is switched off, and then subtracted from the signals in the digital domain when the laser is on. ra 142 o radial actuator fo 143 o focus actuator n.c. 144 - not connected pad table 2. pin description continued all digital inputs and bidirectional pins are 5 v tolerant. symbol pin type [1] description table 3. pin type de?nition type de?nition ai analog input ao analog output aio analog input/output aib analog input or bidirectional id digital input with pull-down idh digital input with pull-down and hysteresis iu digital input with pull-up iuh digital input with pull-up and hysteresis o digital output, slew-rate limited b digital bidirectional, slew-rate limited p power connection
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 10 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder relative gain mismatch is minimized by using carefully scaled circuitry in the time-continuous parts of the signal path, and by time-sharing circuitry in the time-discrete parts. a simpli?ed block diagram of the lf acquisition path is shown in figure 3 . the output of the opu is converted to a current across the input resistor. the current conveyor provides a low input impedance and a high output impedance and sets a virtual earth at the end of the voltage-to-current converter to the same voltage as v ref (1.6 v). the level shifter acts as a summing node for the dc cancellation and produces a current that is referenced to an internal bias voltage which is independent of v ref . the output current charges an integration capacitor c int . when the voltage reaches v dda / 2, the comparator switches and sends a feedback current that has opposite polarity to the input current which tries to discharge the capacitor. the register lfadcgain de?nes the amount of feedback current and so sets the adc gain. a pdm waveform appears at the output of the adc, and is passed through a low-pass ?lter (in the digital domain). the average value at the output of the ?lter is in proportion to the voltage between v i and v ref . input signals from the opu, gpio inputs and the aux inputs are routed to eight adcs comprising six lf adcs and two general purpose adcs. adcs lf1, lf2, gp1 and gp2 are shared by some of these inputs which are routed via an internal multiplexer. adc lf1 is shared by input pairs d1, d2, and aux_l, aux_r via the multiplexer. adcs lf3 to lf6 are dedicated to inputs d3, d4, r1 and r2 respectively. adc gp2 is shared by input pairs gpio0, gpio2, and gpio1, gpio3 via the multiplexer. the internal multiplexer is controlled by register auxandgpadccontrol. (1) if_auxin_sel = 0: d1 and d2 selected; if_auxin_sel = 1: aux_l, aux_r selected. if_gpio_sel = 0: gpio0 and gpio2 selected; if_gpio_sel = 1: gpio1 and gpio3 selected. fig 3. lf acquisition block diagram 001aag307 aux_l, aux_r, gpio1, gpio3 d1, d2, gpio0, gpio2 current conveyor mux level shift 1 0 (1) d, s, gp_bipolar_sel register lfcontrol internal reference1 compin v dd v ss internal reference 2 comp_ref_sel[1:0] register lfcontrol fsl (clock) dx_pdm d1offset; d2offset gp1offset; gp2offset lfadcgain genpurpgain c int dc compensation dac feedback dac feedback switch v ref anti-alias filter (only used on gp inputs)
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 11 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.1.2 hf acquisition the hf data (efm) signal is obtained by summing the signals from the three or four central diodes of the opu and ?ltering and converting the signals to a digital representation via a 6-bit hf adc. figure 4 shows a simpli?ed block diagram of the hf path. the four diode signals d1, d2, d3 and d4 are summed in the ?rst rf ampli?er. the gain of the ?rst ampli?er is controlled by register agcgain[7:4]. a second gain stage has been added to lessen the gain bandwidth requirements of a single gain stage operational ampli?er and also to act as dynamic automatic gain control (agc). the gain of this ampli?er is set by register agcgain[3:0] and can be changed on-the-?y from the arm microprocessor. the gain range accommodates 12 db of gain needed to boost the signal when the laser tracks across a ?ngerprint defect on the disc. cd-r, cd-rw, and ?nger prints, not only reduce the ac signal amplitude compared to a perfectly pressed disc but also reduces the dc pedestal voltage. the high-pass ?lter will remove all dc present at the input, but offsets will be added by the second and third gain stages. a 5-bit plus-sign dac controlled by register offsetcomp[5:0] adds a current to compensate for this offset. the current reduces in linear db steps and follows the ac gain. fig 4. hf acquisition block diagram 001aag308 20 k w rf amp1 0 db ... 24 db register agcgain[7:4] register rfcontrol2[1] high-pass filter d1 20 k w d2 20 k w d3 20 k w 20 k w 20 k w 20 k w 80 k w 80 k w register rfcontrol2[2] single-ended-to- differential 4 converter register offsetcomp[5:0] decoded to [31:0] d4 hf_mon rf amp2 0 db ... 12 db register agcgain[3:0] a noise filter d e g h h g e d c b a b c noise_filt_sel register rfcontrol2[3] register rfcontrol1[6:4] register rfcontrol1[3:0] 67.7376 mhz from pll 67.7376 mhz sys_clk register rfcontrol2[4] register rfcontrol2[0] register rfcontrol2[1] register rfcontrol2[5] rf_adc_out[5:0] to channel decoder
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 12 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder to help users set up the correct gain and dc offset for each particular mechanism, an eye pattern monitor facility is included. this consists of a high frequency buffer ampli?er whose input can be selected to monitor various important nodes within the analog rf path. the monitor point is controlled by register rfcontrol1[6:4] ?eld rfmonsel. the output of the buffer drives hf_mon pin (pin 7). this register also controls the roll-off frequency of the noise ?lter which is in front of the 6-bit adc in the rf path. various blocks within the analog rf path can be powered down if required, including the complete path. these power-down bits are controlled by register rfcontrol2[5:0]. in addition, the 6-bit rf adc can be stand-alone tested in application mode, or a separate external rf path ic can be connected to saa7834 by selecting bit 1 of register rfbypasssel. the input for the rf signal is then via pin hf_mon. in this mode the central diode summing circuit, rf amp1, high-pass ?lter and rf amp2 are all bypassed. 6.2 analog clock generation the saf784x consists of two analog phase-locked loops. the 67 mhz pll is dedicated to the channel decoder. the 152 mhz pll is dedicated to the remaining functionality. the clock strategy for the saf784x is intended to address areas that are prone to noise effects fig 5. analog clock generation 001aag309 clock multiplier variable ratio osc register clkgen cntrl[4] 0 1 hf adc audio dac clock multiplier 8 ? 2 register clkgen cntrl[5] register clkgen cntrl[1] register clkgen cntrl[2] register clkgen cntrl[3] 0 1 register anaclockpllcontrol[3] used for internal test adac_in_8_clk used for internal test sys32k_clk (real time clock) micro_clk (152 mhz) lfadc8m_clk (digital servo) pad_clk1v8 (used for internal test) register anaclockpllcontrol[0] analog to digital interface pads pad_clk3v3 0 1 register clkgen cntrl[0] 0 1 osc
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 13 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder that can decrease the quality of audio. the clocks related to audio dac and lf adc are generated directly from the analog signal, instead of being derived from high frequency plls. the clocking strategy for the digital core is shown in figure 9 . 6.3 general purpose analog inputs the four general purpose adc inputs, gpio0 (pin 33), gpio1 (pin 34), gpio2 (pin 35), and gpio3 (pin 36), can be used for giving the arm microprocessor access to external analog sources, such as monitoring temperature and to provide simple resistor-ladder keypad functionality. these inputs use an additional pair of sigma-delta adcs identical to those used for the lf diode inputs. the general purpose analog inputs have separate interrupt request lines and use address space in the servo registers for storing the converted digital values. the output of the general purpose adcs are low-pass ?ltered and can have ?ne-offset compensation added before being passed to a decimation ?lter. the digital values output from the decimation ?lter are then captured in the servo registers with a resolution of 10 bits per channel. there are only two adcs for general purpose application and so each adc is multiplexed between two inputs: adc1 between gpio0 and gpio2, and adc2 between gpio1 and gpio3. gpio2 and gpio3 inputs are selected by signal auxcontrolandgpadc. 6.4 auxiliary analog inputs analog inputs, aux_l and aux_r, are available, and have suf?cient resolution, for the input of external audio sources, such as allowing arm access to an external audio source for sound processing algorithms. this allows audio processing of external audio sources via the aux pins, whilst simultaneously using the general purpose inputs for keyboard and temperature inputs. since these two inputs share one pair of the lf sigma-delta adcs used in the lf path (for inputs d1 and d2) a multiplexer is used to control the data source into the adcs. therefore, d1 and d2 cannot be used at the same time as aux_l and aux_r. this path is designed for a tuner input where the thd speci?cation is ~0.3 % and the s/n is < 60 db. these performance values are lower than when the normal cd audio path is used i.e. s/n > 80 db and thd < 0.01 %. the audio data is converted to a pulse-density modulated digital stream for both input channels. this data is then low-pass ?ltered and decimated to produce 10-bit representations of the analog inputs. the auxiliary inputs differ from the general purpose analog inputs because the parallel data is converted to an i 2 s format stream and then sent to the i 2 s handler block to make the data available to the arm microprocessor. the i 2 s handler contains a 12-deep data fifo which allows the arm microprocessor to service the audio data with a lower priority than it would need if it were directly registered; see figure 6 .
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 14 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder (1) 10-bit samples of aux_l and aux_r expanded to 16 bits by adding 6 lsbs. (2) i 2 s router block used to route i 2 s to audio dac or pins. fig 6. auxiliary analog inputs block diagram 001aag310 pdsic adc s 1 d1 or aux_l s 2 c mux d d1 aux_l spare reg a s 1 d2 or aux_r d1 or aux_l d2 or aux_r lpf decimation filters serial out data bclk vpb-bus wclk (1) i 2 s router (2) d1 or aux_l d2 or aux_r s 2 c mux d d2 aux_r lf_auxin_sel
xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxx x x x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xx xx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxx x x xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx xxx saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 15 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder fig 7. clocking top-level block diagram 001aag311 clock generator 152 mhz subsys clock 67 mhz channel clock 4.2336 mhz audio dac clock osc_32k_in osc_32k_out block decoder ahb registers seg. man dma timer ( 2) audio dac i 2 c i 2 s handler wdt uart ( 2) rtc gpio pdsic smiu ahb / vpb interface ram ahb vpb arm arm / ahb 32 khz clock vpb slaves clock 8.4672 mhz pdsic clock 8.4672 mhz i 2 c clock i 2 s bit clock rom clock generator cd slim analog clock generator oscin oscout
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 16 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.5 channel decoder 6.5.1 features the channel decoder in the saf784x is derived from the design used in the saa7817hl dvd decoder ic. the design has been optimized for cd decode functionality (efm and demodulation is removed) and has the following features: ? one-channel interface to the on-chip 6-bit 67 mhz adc ? signal conditioning logic with high-pass ?lter, dc-offset cancellation (aoc) and agc logic ? hf defect detection circuitry with automatic hold of agc, aoc, hpf, pll and slicer on defect detection ? digital equalizer, noise ?lter, pll and slicer ? run length 2 (rl2) push back mechanism ? efm demodulator with sync interpolation ? cd text and subcode q-channel extraction blocks with software interface via registers ? decoding, de-interleaving and reed-solomon error correction according to cd circ standards ? on-chip de-interleaving sram memory ? audio processing back end with interpolate/hold, mute, kill and silence detect logic, de-emphasis and 4 upsample ?lter ? two data output interfaces: i 2 s and ebu ? one serial subcode output interface (v4) ? motor control for clv (locked-on efm) or cav (locked-on tacho) or open loop or software-controlled regulation with one or two motor pins ? on-board tacho measurement with one or three hall sensor inputs (t1 to t3), that provides frequency input for motor loop; the sensor inputs are shared with gpio pins ? 8-bit register map, with ahb slave interface ? an interrupt output with associated interrupt, status and interrupt enable registers for full interrupt-driven operation ? debug information available via meas1 (cl1, pin 97) and pin cflg (pin 95) and parallel debug bus 6.5.2 block diagram the incoming diode signals are ?rst added and processed in the analog front end to create a normal rf (hf) signal and then converted to digital by the adc. this signal is then resampled from the adc clock to the system clock domain via the integrate-and-dump block. offset and gain on the rf signal is removed via the agc/aoc loop (via the analog front end). any remaining offset which is not removed by the analog front end can be removed via the digital hpf. the rf signal is then sliced by the bit detector, clock recovery is done by a full digital pll with noise ?lter, equalizer and sample-rate convertor. a defect detector allows agc, aoc, hpf, slicer and pll to be held during black or white dots. at this point in the data path, rf samples are converted into a bit stream. the rl2 push back avoids rl3s in the rf being accidently translated into rl1 or rl2 in the bit stream. the channel bit stream is demodulated in to bytes by the efm demodulator. q-channel subcode and cd-text information is extracted via the q-subcode
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 17 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder and cd-text decoder, available for readout through the sub-cpu interface. the main data stream is error-corrected by the erco, while the memory processor takes care of the circ de-interleaving and buffering of data in a fifo. at the back end of the channel decoder, corrupted audio samples can be interpolated and held, while a burst of errors can trigger the mute block. detection of digital silence can be used to kill the internal or external audio dac. pre-emphasis on the audio disc can be removed via the de-emphasis ?lter, and the data can be 4 upsampled before it is sent to the audio dac. cd data is output via the i 2 s and/or the ebu outputs. motor control can be frequency-regulated to the incoming rf bit rate, with additional phase regulation by fifo ?lling, or it can be fully controlled via software. this method guarantees clv support. a tacho measurement block is also available. the motor can also be regulated by the tacho frequency which allows possible cav support. debug information is available via registers, via the dedicated serial lines meas1 and c?g. the arm ahb address of registers that control speci?c logic are shown next to each functional block in figure 8 .
xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxx x x x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xx xx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxx x x xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx xxx saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 18 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder fig 8. channel decoder top-level block diagram 001aag312 diode signals from rl2 pushback rl2 pushback digital equalizer noise filter src hpf integrate and dump adc analog offset measurement memory processor (circ decoder and fifo) subcpu and general slice level determine zero trans detect efm demodulator interpolate/ hold kill generation ebu interface interrupts rms jitter measurement upsample q-subcode motor control silence detect error detect de- emphasis peak detectors defect detector peak detector i 2 s tacho clock shop soft mute erco hard mute digital pll cd-text agc aoc to demodulator multiplex pll frequency jitter value slice level moto 1 i 2 s clocked on pll clock moto 2 t2 t1 t3 left kill right kill meas1 cflg error correction info hold hold 0 3000 0000 0 3000 00d0 0 3000 0168 0 3000 013c 0 3000 012c 0 3000 0130 0 3000 01e0 0 3000 01e0 0 3000 01f0 0 3000 01f0 0 3000 01e0 0 3000 01ec 0 3000 01f0 0 3000 01dc 0 3000 01e8 0 3000 01e8 0 3000 0160 0 3000 00a0 0 3000 0060 to 0 3000 00a0 0 3000 0170 to 0 3000 0178 0 3000 01e0 to 0 3000 01e4 0 3000 0174 0 3000 0180 to 0 30000184 0 3000 01b0 to 0 3000 01bc 0 3000 01a0 to 0 3000 01a8 0 3000 00d4 to 0 3000 00d8 0 3000 00a4 to 0 3000 00bc 0 3000 00f0 to 0 3000 0104 0 3000 (0120 to 0128), 0 3000 (0134 to 0138) 0 3000 0148 0 3000 (0140 to 0144) 0 3000 (0020, 0240, 0248, 024c) 0 3000 0000 to 0 3000 000c 0 3000 0210 to 0 3000 022c 0 3000 0260 to 0 3000 026c 0 3000 01d0 to 0 3000 01d4 0 3000 0040 to 0 3000 004c 0 3000 0244
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 19 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.5.3 clock control the clock control block de?nes the clock frequencies for four clock domains. (1) 66 mhz is an approximate value. fig 9. clock control block diagram 001aag313 hf_clk (66 mhz) cl1clk cl16clk sysclk ebuclk 33 mhz (50 %) bitclk bclk_in bclk bclki cl16 ebuclk ebuclki fastclk phi3 phi2 phi1 sys_always_on sysclk cl1 xclk (66 mhz) (1) block decoder/encoder interface clocksys_div (pulse blanking) /1 (33 mhz), /2 (16 mhz) /4 (8 mhz), /8 (4 mhz) /16 (2 mhz) cl1_div (50 %) /1, /2, /3, /4 integrate and dump clockebu_div (50 %) /2, /3, /4, /6, /8, /12, /16, /24, /32, /48 cl16_div (50 %) /3, /4, /6, /8 clockbit_div (50 %) /2, /3, /4, /6, /8, /12, /16, /24, /32, /48 ? 2
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 20 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder ? xclk: most internal clocks are derived from the crystal clock. this clock is the output of the clock multiplier in the analog part and has a ?xed frequency of 67.7376 mhz = 8.4672 mhz (f xtal ) 8. if a 16 mhz crystal is used, the crystal clock is divided by 2 inside the analog block. crystal selection is done via analpllcontrol bit sel16. ? sysclk domain: the system clock, or its derivatives, runs the main part of the internal channel decoder. the sysclk is derived from xclk divided by 2 (50 % duty cycle) and can be further divided down via register sysclockcon?g bit sysdiv. this register also allows the majority of clocks to be powered down (for sleep mode). the choice of the sysclk frequency f clk(sys) in an application is determined by the expected input bit rate f bit of the rf bit stream. the relationship between this incoming bit stream frequency and the system clock frequency f clk(sys) is expressed by the ratio f bit /f clk(sys) . there are two limiting factors: C the hf-pll operating range is between 0.25 (f bit / f clk(sys) ) and 2 (f bit /f clk(sys) ) C the decoder and error corrector throughput rate is limited to 1.7 (f bit /f clk(sys) ) this brings the constraint to 0.25 < f bit / f clk(sys) < 1.7. ? bitclk domain: runs the i 2 s back-end logic. the bit clock (bitclk) is also output as part of the i 2 s interface. in audio slave mode this clock must be programmed to be exactly 44100 hz 2 16/24/32 (depending on i 2 s mode), to get a 1 data rate to the audio dac. in master mode with gated bitclk, the bitclk must be programmed to be at a higher rate than the outgoing bit rate required for the disc speed, to avoid fifo over?ow in the decoder. for example, at n = 1, the incoming rf bit rate = 4.3218 mhz, which corresponds to an output bit rate of 1.4112 mhz. this means that the bitclk frequency is above 1.4112 mhz and is high enough when i 2 s-16 is chosen, while i 2 s-32 requires the bitclk to be at least 2.8224 mhz. the bitclk division is selected via register bitclockcon?g. also, bitclk gating can be enabled via the same register. ? ebuclk domain: runs the ebu back end. the ebu (or s/pdif) interface is only enabled during audio slave mode. the ebuclk needs to be exactly 44100 hz 64 = 2.8224 mhz for 1 operation. the ebuclk division is selected via register ebuclockcon?g. the following clocks are also controlled by the clock control block: C the hf_clk is ?xed at 67.7376 mhz, and is used to clock-in the samples from the adc, which is clocked by the xclk with the same clock frequency C the bclk_in is the incoming i 2 s bit clock, which is used when i 2 s is programmed to receive bclk rather than transmitting it (programmed via register i2scon?g) C the cl1clk can be used to monitor the c?g and meas1 debug lines. the frequency can be programmed via register clclockcon?g C the cl16clk can be used to clock an external audio dac or audio ?lter ic. the frequency can be programmed via register clclockcon?g 6.5.4 decoder-arm microprocessor interface the decoder core is internally connected to the arm core via the ahb interface for register access to the decoder internal con?guration registers. 6.5.4.1 programming interface decoder registers are programmed through the ahb interface. the programming interface is not fully described in this document.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 21 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder for the application, it should be noted that the interface supports 32-bit registers, while the decoder only contains 8-bit registers. therefore, the decoder registers are treated as 32-bit registers of which the 24 msbs are not used. the register address map occupied by the decoder goes from relative address 0x3000 0000 to address 0x3000 0374, and can be split into two parts: 0x3000 0000 - 0x3000 024c: the decoders own registers - used to con?gure the channel decoder, and the functionality they control is described in detail in this section. 0x3000 02a0 - 0x3000 0374: the decoder immigrant registers - used to control parts of the saf784x that do not have their own ahb interface (they are not used to control the decoder channel decoder). 6.5.4.2 interrupt strategy the channel decoder contains two interrupt status registers: interruptstatus1 contains all interrupts that operate as set/reset latches (set by hardware, reset by reading from the register). interruptstatus2 contains all interrupts that operate as feed-throughs (set by hardware, reset by hardware or by accessing other registers). each interrupt bit can be enabled or disabled separately by writing to its corresponding enable bit in the interruptenable1 and interruptenable2 registers. if one or several interrupt bits are set and at least one is enabled, the interrupt line of the decoder to the microcontroller will go active (low). if an interrupt bit is disabled (enable bit turned off), it is prevented from activating the interrupt line to the microcontroller. however, this mode allows the interrupt to be processed if the status register is polled instead of interrupt handling by the microcontroller. 6.5.5 efm bit detection and demodulation a block diagram of the bit recovery is shown in figure 10 . the hf signal comprises the four diode inputs inside the analog block. it is pre-processed (lpf, hpf, offset removal and gain adjustment) and then sampled by a 6-bit adc. on the sampled hf, bit recovery is done by means of a full digital pll and slicer. before the sampled signal enters the pll section, it is pre-processed by a signal conditioning block. this consists of an integrate-and-dump block, a high-pass ?lter and logic available for gain control and offset control on the rf signal in the analog section. for good playability on defects, a defect detector puts the pll, the slicer, the agc, the offset cancellation and the high-pass ?lter into hold during defects. fig 10. bit recovery block diagram 001aag314 d1 d2 d3 d4 to demodulator agc aoc signal conditioning block 6-bit adc analog block pll and bit slicer
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 22 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder the detected bits are then sent to the demodulator for sync extraction and efm demodulation. for playing on damaged or out-of-speci?cation discs, ?ywheels are in place to make the sync extraction more robust. 6.5.5.1 signal conditioning this device has a number of blocks which process the incoming 6-bit hf signal. ? integrate-and-dump block to adapt the frequency of the adc to the system clock ? peak detection logic for amplitude measurement ? peak detection logic for dc-offset measurement ? digital high-pass ?lter with con?gurable cut-off frequency ? dc and gain control logic for on-board variable gain and offset control (in the analog section) ? a defect detector all blocks can be con?gured under microprocessor control. integrate-and-dump block: the adc delivers one sample every xclk period (= one sample every hf_clk period). the sample rate needs to be adapted from this xclk rate to the lower sysclk rate. for more information on sysclk speed, see section 6.5.3 on page 19 . the integrate-and-dump block converts the incoming samples at the hf_clk frequency into a stream of one sample per sysclk period. it converts an average of a number of samples to achieve this. if the division factor for the system clock is /2, /4, /8, /16, /32, an average of 2, 4, 8, 16 or 32 incoming samples respectively, is taken and passed further. this results in a gain in the number of effective bits of the a-d conversion. high-pass ?lter: a 1st-order iir high-pass ?lter with a variable 3 db point is implemented to ?lter out the remaining dc jump-on defects. most of these defects will have been ?ltered by the analog hpf. the cut-off frequency of the digital high-pass ?lter can be changed on-the-?y, by writing to register highpassfiltcont. it is possible to reset the state of the high-pass ?lter via bit 6 of register highpassfiltcont. the input and the output of the high-pass ?lter are 8-bits wide. the high-pass ?lter is implemented in a 1 minus low pass structure. it is possible to hold the low-pass ?lter on defects. for more information, see section def ect detector on page 26 . fig 11. signal conditioning block diagram 001aag315 hold hold signals to bit detection hf data to bit detection integrate and dump adc analog hpf offset measurement peak detector peak detector defect detector agc/ aoc
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 23 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder the high-pass ?lter works on the system clock. its bandwidth is also proportional to the sysclk. a formula for approximating the cut-off frequency (f c ), of the high-pass ?lter is: (1) peak detectors: the signal conditioning block has two types of peak detector: ? peak detector with decay ?lter: works on an immediate attack/slow-decay basis, and is used for measuring peaks, amplitude and offset, read by software which sends peak information to the defect detector. ? peak detector based on window: works on the principle of detecting maximum and minimum peaks within a window, and is used for the agc and aoc control logic. both peak detectors monitor the rf after it has passed an optional noise ?lter. this noise ?lter is a lpf with a programmable high cut-off frequency. this bandwidth is programmed via register pdbandwidth bit noisefilterbw for the noise ?lter before the peak detectors of agc/aoc and measurement read back. the defect detector peak detector has its own noise ?lter which is programmed via register defectdetpeakbw bit noisefilterbw. peak detector with decay ?lter: the functional schematic of this peak detector is shown in figure 12 . the maximum and minimum peaks of the incoming signal are measured at the inputs of switches s1 and s2 respectively. the maximum and minimum peak signal paths both have a decay ?lter with a long time-constant and matching bandwidth. the maximum peak decay ?lter responds to the smallest value possible. the decay ?lter for the minimum peak responds to the largest value possible. the decay bandwidth of the measurement readback decay ?lter is controlled by register pdbandwidth bit decaybw, the bandwidth of the defect detector is controlled via register defectdetpeakbw bit decaybw. the following settings of the decay ?lters are possible: c = 1 - 2 - m , for m = 6 to 21, where c = time-constant coef?cient, m = decaybw[3:0] + 6. (1) determines the time-constant coef?cient. fig 12. peak detection block with decay ?lter f c hpf , hpset 5:0 [] 2 p 2 11 ----------------------------- - f clk sys () = 001aag316 max peak s1 noise filter decay filter min peak hf_in s2 decay filter (1) (1)
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 24 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder the bandwidths and corresponding time-constant (t) of the decay ?lter are shown in t ab le 4 , when the system clock frequency f clk(sys) is 10 mhz. peak detector based on window: the functional schematic of this peak detection is shown in figure 13 . the minimum and maximum peaks of the incoming signal are measured during a programmable window period. the highest and lowest sample within this window are used to update maximum and minimum peaks. the window width of the measurement is controlled via register agcaoccontrol bit pdmeaswindow. agc and aoc control block: the agc control block controls the rf amplitude at the input of the adc by controlling the gain of an on-chip analog gain ampli?er. the aoc control block controls the rf offset at the input of the adc by adding or subtracting the offset just before the adc. both agc and aoc loops are built up in the same manner and are shown in figure 14 in their relative position within the signal conditioning block. table 4. decay ?lter time-constants at f clk(sys) = 10 mhz m t m t m t m t 6 6.35 m s 10 102.4 m s 14 1.64 ms 18 26.21 ms 7 12.75 m s 11 204.7 m s 15 3.28 ms 19 52.43 ms 8 25.55 m s 12 409.6 m s 16 6.55 ms 20 104.8 ms 9 51.15 m s 13 819.2 m s 17 13.11 ms 21 209.7 ms fig 13. peak detection block with window 001aag317 max peak window width 0 noise filter min peak hf_in
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 25 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder the maximum and minimum peaks on the envelope of the rf signal after the adc are ?rst measured via a noise ?lter and the window peak detector (see section p eak detectors on page 23 . the amplitude is then calculated as maxpeak - minpeak, and the offset as (maxpeak + minpeak) / 2. for tuning the loops, it is possible to read back the hfmaxpeak, hfminpeak, hfamplitude and hfoffset, as measured from their registers by the decay peak detector. agc control: the rf amplitude at the adc input can be changed with two gain ampli?ers in the analog part: g1 (?xed) and g2 (dynamic). g1 has a gain range from 0 db to 24 db in 16 steps of 1.6 db, while g2 has a range from 0 db to 12 db in 16 steps of 0.8 db. both gains can be programmed via register agcgain. g1 will stay ?xed, while g2 can be regulated by hardware when the agc is turned on. the agc will regulate the gain such that the measured amplitude stays between a programmed upper threshold (agcthrhi) and lower threshold (agcthrlo). if the amplitude is smaller, gain will increase; if the amplitude is too large, gain will decrease. when clipping is detected on either one or both sides, the gain will decrease. these gain changes are not sent to the analog gain ampli?er directly but are integrated over time. only if, on average, a gain increase or decrease is requested, will this result in a real gain increase or decrease of the ampli?er. this can also be read back via register agcgain. the agc, together with the noise ?lter on the peak detector, prevents rf noise causing over-sensitive gain regulation. to further reduce sensitive behavior, a hysteresis window with a width of one gain step is added between the integrator and ampli?er g2. the bandwidth of the gain loop determines how fast it reacts to ?ngerprints and scratches; it is programmed via register agcintegbw. it is also possible to limit the range of g2 by programming a maximum and minimum boundary by register agcgainbound. aoc control: most of the rf offset at the adc input will be removed by the analog hpf (1st-order hpf with 3 db point around 3.6 khz). the remaining offset (mainly introduced by the analog front end), can be removed by adding or subtracting a ?xed offset in the analog part. this offset subtraction/addition has a range of 32 steps in each direction, with approximately 1.4 lsbs per step (referenced to the rf adc). this leads to a full fig 14. agc and aoc loops 001aag318 hpf (digital) 6 msbs k gain software/ defect integrator lo hi - 1 +1 - 1 +1 to bit detection g1 g2 g3 hpf analog defect detect registers integrator clipping detect decay peak detector window peak detector decay peak detector integrate and dump filter nf (lpf) nf (lpf) adc k offset software/ defect lo hi 4 msbs
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 26 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder correction range of 42 lsb steps (more than the whole adc range). this offset compensation (offset comp) value can be programmed via register offsetcomp, and will be regulated in hardware as soon as the aoc is turned on. the aoc will regulate the offset comp value such that the measured offset stays within a window programmed by register offsetbound. the offset comp value decreases if the offset is above this window, and increases if the offset is below the window. if an inversion occurs on the rf signal between analog and digital, the reaction of this loop can be inverted by programming offsetbound bit offsetinv. the offset changes are not sent to the analog offset subtraction directly, but are integrated over time. only if, on average, an offset increase or decrease is requested, this will result in a real offset increase or decrease of the analog addition. this can also be read back via register offsetcomp. the aoc, together with the noise ?lter on the peak detector, prevents rf noise causing over-sensitive offset regulation. to further reduce sensitive behavior, a hysteresis window with a width of one offset step has been added between the integrator and offset comp value. the bandwidth of the offset loop will determine how fast it reacts to ?ngerprints and other defects; it is programmed via register offsetintegbw. it is also possible to limit the range of the offset comp value by programming a maximum and minimum boundary by register offsetcompboundhi and offsetcompboundlo. agc/aoc general and rules-of-thumb: the agc and aoc hardware regulation loops can be enabled or disabled separately via register agcaoccontrol. this register also allows the use of a slow agc and/or aoc loop. in this case the programmed loop bandwidth is decreased with an extra factor of 128. in this mode the loops will be too slow to react to defects, but can be used for a slow software-like gain and/or offset regulation to regulate the average gain and offset over the disc comfortably within a speci?ed range. an important feature is the agcaoccontrol bit disholdnolock, which disables holding of the agc and aoc loops during defects (triggered by the defect detector, see section def ect detector on page 26 while the hf pll is not in lock. this feature avoids permanent lockups of the loops caused by a small amplitude triggering the defect detector, which in return would hold the agc loop. the following things should be taken into account as general rules-of-thumb: ? the amplitude thresholds should not be programmed too close to each other: allow at least two gain steps (1.6 db) from lower to higher boundary and vice versa to avoid an over-sensitive agc. ? the offset boundary should not be programmed too tight: 8 is a good value to avoid an over-sensitive aoc. the bandwidth of the loops should never be programmed to be too wide (fast) with respect to the peak detector measurement window, to avoid an unstable loop. if the pdwindow = 2 n f clk(sys) (hz) wide, the bandwidth of the loops should never be higher than 2 -(n+1) (hz). defect detector: the defect detector detects the presence of black or white dots in the rf stream, and freezes some signal conditioning and bit recovery logic during these defects. this prevents the control loops inside this logic drifting away from their optimal point of operation when there is no rf present, so that they can recover very fast when good rf is present again.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 27 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder the detection of a defect is based on amplitude. the amplitude is measured via a set of peak detectors with decay, as described in section p eak detectors on page 23 . the decay bandwidth and noise ?lter bandwidth are programmed by register defectdetpeakbw. two thresholds can be programmed. a low threshold will trigger a defect-detected signal as soon as amplitude goes below this threshold. a high threshold will clear this defect-detected signal again as soon as amplitude goes above this threshold. together, these thresholds apply a hysteresis to the defect detection, avoiding a jittery defect-detected signal (having many on/off parts) when the amplitude is at the threshold edge. thresholds are programmed in register defectdetthres. the defect-detected signal can be used to hold the pll, slicer, agc, aoc and hpf during a defect. the feature(s) that will be held can be programmed in register defectdetenables. the same register can be used, via software, to force the pll, slicer and hpf to hold. the agc and aoc can be held in software by just disabling the loops in register agcaoccontrol. two special features exist on the defect detector: ? optional delay of the enabling and disabling of hold features at the beginning and end of a defect. this can be done by programming a start and/or stop delay (in number of sysclks) via register defectdetstartstopdelay. whenever the defect detector detects the start of a defect, it will wait for the start delay before triggering a defect-detected processed signal. when the defect detector detects the end of a defect, it will wait for the programmed stop delay before clearing the defect-detected processed signal again. this also means that defects which are smaller than the start delay are ignored, and that if the defect contains zones with good rf amplitude but smaller than the stop delay, they are also ignored. in reality, all hold features are triggered by the defect-detected processed signal, rather than the defect-detected signal; at the decoder output, both delays are zero, so both signals are equal. ? optional programmable time-window at the end of a defect, during which, higher pll and/or slicer bandwidths can be used to speed up the recovery of these loops after a defect. this window can be programmed via register defectdethighbwdelay. bandwidth programming is explained in section 6.5.5.2 on page 28 . the detection of the beginning or end of a defect, with or without start and stop delays, can be used to generate an interrupt. see register interruptenable1.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 28 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.5.5.2 bit detector the bit detector block contains the slice-level circuitry, a noise ?lter to limit hf efm signal noise contribution, an equalizer, a zero-transition detector, a run-length push-back circuit, a digital pll and jitter measurement logic. all processing is performed on the bit clock, and bandwidths are proportional to the channel bit rate. to achieve this, rf data is resampled from the system clock domain to the bitclk domain by making use of a sample-rate convertor. blocks can be con?gured under microcontroller control and are described in detail in the next paragraphs. noise ?lter: the digital noise ?lter runs on the channel bit clock frequency f clk(bit)ch . it limits the bandwidth of the incoming signal to 1 4 of the channel bit clock frequency. passband: 0 f clk(bit)ch to 0.22 f clk(bit)ch (hz) stop-band: (0.28 f clk(bit)ch ) to (f clk(bit)ch - 0.28 f clk(bit)ch ) (hz) rejection: - 28 db slice-level determination: the slice-level determination circuit compensates for the incoming signal asymmetry component. bandwidth of the slice-level determination circuit is programmable via register slicerbandwidth. also the higher bandwidths for use after a defect (see section def ect detector on page 26 ) are programmed in this register. the bandwidth is proportional to the channel bit clock frequency. the slice level, or asymmetry, can be read back via register slicerassym. equalizer: in the bit detection circuit, a programmable equalizer is used to boost the high frequency content of the incoming signal. the equalizer includes an integral ?ve-tap presentable, asymmetrical equalizer. the equalizer block diagram is given in figure 16 . fig 15. bit detector block diagram 001aag319 clocked on pll clock multiplex to demodulator meas1 jitter value from signal conditioning - pll frequency slice level src noise filter digital pll rms jitter measurement rl2 pushback digital equalizer slice level determine zero transition detect
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 29 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder the ?rst and last tap can be programmed via register pllequaliser. usable efm bit clock range: the channel bit clock frequency f clk(bit)ch must obey the following constraints in relation to the system clock frequency f clk(sys) . the channel bit clock frequency must always be: ? less than f clk(sys) 2 (hz) ? greater than f clk(sys) 0.25 (hz) therefore the range is: f clk(sys) 0.25 < f clk(bit)ch saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 30 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder f 1 : integrator cross-over controlled via k i f 0 : pll bandwidth controlled via k p f 2 : lpf bandwidth controlled via k f the three frequencies are programmable using register pllbandwidth. the higher bandwidths for use after a defect, are programmed in register pllbandwidthhigh; see section def ect detector on page 26 . when the pll is in lock, the recovered pll clock frequency equals the channel bit clock frequency. detection of pll lock: the pll locking state is determined by the distance between detected syncs. this means that the sync detection is actually controlling the automatic pll locking. the pll switches from outer lock to inner lock when successive syncs are detected to be 588 25 channel bits apart. internally this is also called a winsync (sync falls in a wider window). the number of missed winsyncs is kept in a 3-bit con?dence counter, and the pll will go out of outer lock when seven consecutive out-of-window syncs are found. the pll switches from inner lock to in-lock when successive syncs are detected 588 1 channel bits apart. the number of consecutive missed syncs is kept in a bit counter, and saturates on either 16 or 61, depending on the value of bit lock[16] or [61] in register demodcontrol. when the saturation level is reached, the pll is set out-of-lock. the pll frequency (inner-) and phase (in-) lock status can be read out in register plllockstatus. pll outer-lock aid: the outer lock aid has no limitation on capture range, and will bring the pll within the range of the inner lock aid. the pll will ?rst regulate its frequency based on detecting rl3s as the smallest possible rls (fast-but-rough regulation), and next on detecting rl11s as the largest possible rls (slow but more accurate). pll inner-lock aid: the inner-lock aid has a capture range of 4 %, and will bring the pll frequency to the phase-lock point. it will regulate the pll frequency such that 588-bits are detected between two efm-syncs. in?uencing pll behavior: programmability and observer ability are built into the pll mainly for debugging purposes, and also to make dif?cult applications possible. the pll operation can be in?uenced in two ways: fig 17. pll bode diagram 001aag321 loop gain frequency f 1 f 0 f lpf
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 31 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder ? optional manual selection of the pll state (in-lock, inner-lock, outer-lock, outer-lock with only rl3 regulation). ? optional pre-set of the pll frequency to a certain value overriding the pll state: pll state can be: ? in-lock ? inner lock ? outer lock ? outer lock with only rl3 regulation ? hold normally, the pll state is selected automatically by the lock detectors. however, the pll lock state can be overruled via register plllockaidcontrol. when lock mode is left at 0, the user can still choose the pll state, but hardware will overwrite this if the hardware-selected pll state is closer to locking the pll. [1] during pll hold, the pll frequency will not change and the frequency preset may be used. it is possible to pre-set the pll frequency to a certain value by writing the integrator value of the pll to register pllintegrator. the relationship between the bit frequency, the integrator value, and the sysclk frequency f clk(sys) is given by: (2) the real-time value of the pll frequency can be read at the same address. 6.5.5.3 limiting the pll frequency range the range over which the pll can capture the input frequency can be limited. the minimum and maximum pll frequency can be set by bits minintfreq, and maxintfreq respectively in register pllminmaxbounds. 6.5.5.4 run length 2 push-back detector if this circuit is switched on, all run length one and two symbols (invalid run lengths) are pushed back to run length 3. for rl2s, the circuit will determine the transition that was most likely to be in error, and shift transition on that edge. this feature should always be turned on, but can be deselected via register rl2pushback. table 5. pll lock states lock mode plllockcontrol state [1] 0 0 0000 automatic lock behavior 1 0 0001 force hf pll into in-lock 1 0 0110 force hf pll into inner-lock aid 1 0 0100 force hf pll into outer-lock aid 1 0 1000 force hf pll into hold mode 1 1 0100 force hf pll into outer-lock aid with rl3 regulation only x others reserved f clk bit () ch pllfreq 7:0 [] 4 + 128 ----------------------------------------------- f clk sys () hz () =
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 32 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.5.5.5 available signals for monitoring the operation of the bit detector can be monitored by the microcontroller via an external pin. five signals are available for measurement: pll frequency signal: the microcontroller monitors this signal by reading register pllintegrator. asymmetry signal: this signal is in 2s complement form and can be read from register slicerassym. jitter signal: a jitter measurement is done internally. the zero-crossing jitter value is available in register plljitter. internal lock ?ags. jitter signal: jitter measurement is done in two steps: 1. the distance between the efm zero transition and the bit clock zero transition is measured. 2. the calculated jitter for the zero transition is averaged using a 10-bit low-pass ?lter. the top 8-bits of the ?lter output can be read back from register plljitter. to obtain the jitter in % of the channel bit clock, equation 3 applies: (3) this jitter measurement is also available via the meas1 telemetry signal on pin cl1. the full 10-bit output of the ?lter is available via this pin; see section 6.5.5.8 . it is also possible to read out an average jitter value via register pllaveragejitter. this value is an average of the normal jitter value over a period of 8000 bit clock periods. the formula to transform this into a percentage is shown in equation 4 : (4) 6.5.5.6 use of jitter measurement the jitter measurement is an absolute-reference jitter measurement. it gives the average square value of the bit detection jitter. note that bit-to-clock jitter is measured. in this device, the bit-to-clock jitter is measured directly before the bit detection, and contains contributions due to various imperfections of the complete signal path: ? disc table 6. jitter input calculation distance ( f bit ) average distance (bit clocks) jitter ?lter input (5-bit decimal integer) < 2 16 1 16 1 2 16 to 4 16 3 16 9 4 16 to 6 16 5 16 25 > 6 16 7 16 49 jitter jitter 7:0 [] 2.83 C 1024 ------------------------------------------- - 100 % () = average jitter averagejitter 7:0 [] 2.83 C 1024 ---------------------------------------------------------------- - 100 % () =
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 33 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder ? analog preampli?er ? adc ? limited bandwidths in this device ? limited pll performance ? in?uenced by internal noise ?lter, asymmetry compensation and equalizer the jitter measurement is absolute reference, because it relates directly to the efm bit error rate if the disc noise is gaussian. 6.5.5.7 internal lock ?ags the fourth signal that can be monitored are three ?ags in the plllockstatus register: the internally generated inner lock signal flock, the internally generated lock signal inlock and a longsym(bol) ?ag when run length 14 is detected (run length too high). in automatic mode, the flock and inlock ?ags determine what type of pll capture aid is used. 6.5.5.8 format of the measurements signal meas1 on pin cl1 this signal is output via pin cl1 (pin 97) and comprises three measurement signals multiplexed together. the format is shown in figure 18 and t ab le 8 . the data is sent in a serial format. it consists of a pause, followed by a start bit, followed by data bits. bit length: four system clock periods; frame length: 64 bits. table 7. determining the current pll capture mode flock ?ag inlock ?ag capture mode 0 0 outer-lock aid 1 0 inner-lock aid x 1 in-lock fig 18. format on measurement pin cl1 table 8. data format on measurement pin cl1 bit value description 0 '1' start bit [1] 1 to 10 jitter(9) to jitter(0) ?rst sample of jitter word [2] 11 '0' 12 '1' intermediate start bit 13 to 22 pllfreq(9) to pllfreq(0) pll frequency word 23 '0' 24 '1' intermediate start bit 25 to 32 asym(7) to asym(0) slicer level 33, 34, 35 '0' 000 001aag322 pause start bit data bits
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 34 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder [1] the start bit is always preceded by 17 pause bits. the intermediate start bits at bit locations 12, 24 and 36 guarantee that no other '1' value is preceded by 17 0 bits. this allows a simple start bit detection circuit. [2] the jitter word is sampled twice in every frame. the percentage jitter is calculated using equation 5 : (5) 6.5.5.9 demodulator the demodulator block performs the following functions: ? efm demodulation using a logic array ? sync detection and synchronization ? sync protection 6.5.5.10 efm demodulation each efm word of 14 channel bits (which are separated from each other by three merging bits) is demodulated into one data byte making use of the standard logic array demodulation as described in the cd red book (iec 60908) . 6.5.5.11 sync detection and synchronization the efm sync pattern is a unique pattern which is not used anywhere else in the efm data stream. it consists of 24 bits: rl11 + rl11 + rl2. an internal sync pulse is generated when two successive rl11s are detected. a sub-sync pulse is produced when the beginning of a new subcode frame is seen. this is done by analyzing the subcode information: when two successive subcodes are subcode sync-code s0 and s1, sub-sync will be activated. 6.5.5.12 sync protection the sub-sync pulse is protected by an interpolation counter, this counter uses the fact that a subcode frame is always 98 subcode symbols long. the sync signal itself is also interpolated. if after 33 data bytes (one efm frame), no new sync is detected, it is assumed that the bit detector has failed to correctly produce it, and the sync signal is given anyway, this is generally called an interpolated sync. furthermore, if a new sync is detected in the data shortly after a previous sync signal, interpolated or real, no new sync signal will be produced, because this means the frame has slipped. after enough data byte periods, the sync signals are allowed to pass again. although the possibility is small, false syncs can be detected, such as corrupted efm bits that accidentally form the combination rl11 + rl11. if two, or three, of such false re-syncs are detected at the correct distance from each other, this would cause a false sync of the demodulator. such a re-sync could lead to a large number of samples being corrupted at the output of the circ decoder. the chance of false sync detection is greatest during defects (black and white dots). 36 '1' intermediate start bit 37 to 46 jitter(9) to jitter(0) second sample of jitter word [2] 47 to 63 '0' pause table 8. data format on measurement pin cl1 continued bit value description j itter jitter 9:0 [] 12.81 C 4096 ---------------------------------------------- - 100 % () =
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 35 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder to prevent such false demodulator re-syncs, two features are built in, which are both programmable via register demodcontrol: ? robustcntresync: this feature should always be turned on: when it is on, the demodulator will look for three consecutive syncs instead of two, with correct in-between distance before re-syncing. this should greatly improve the robustness against false syncs. ? syncgating: when 1, the sync detection is turned off during a defect, to avoid the detection of false syncs; when 0, sync detection is left on permanently. note that the defect detector needs to be set-up properly before this feature can be used. for this reason, this feature is turned off by default after reset. 6.5.6 cd decoding 6.5.6.1 general description of cd decoding the decoder block performs all processing related to error correction and circ de-interleaving and makes use of an internal sram fifo which provides the necessary data capacity. it also extracts the q-channel subcode and the cd-text information from the data stream and delivers it to the application via a register interface. 6.5.6.2 q-channel subcode interface the channel decoder contains an internal buffer which stores the q-channel bytes of a cd-subcode frame. this subcode can be retrieved by the microcontroller, by accessing the registers subcodeqstatus, subcodeqdata and subcodeqreadend. to start retrieving the subcode, the microcontroller must ?rst read the register subcodeqstatus. this register contains various status bits that indicate the status of the q-subcode that may be read. when, after reading the register subcodeqstatus, the qready bit is found high, the q-subcode interface will be blocked (indicated by qbusy going high) so that no new subcode will overwrite the current one. qcrcok indicates if the current subcode frame was indicated correctly, or not, by a hardware crc check. after reading subcodeqstatus with qready = '1', the microcontroller may retrieve as many subcode bytes as required (10 maximum) by issuing subsequent reads to register subcodeqdata. the content of the q-channel subcode in the main data area is described in t ab le 9 . for a description of the content during the lead-in area, refer to the cd red book (iec 60908) . table 9. q-channel subcode frame content address/byte name comments 1 control/mode 2 tno 3 point 4 rel min mod100 relative time 5 rel sec mod 60 6 rel frame mod 75 7 zero 0 or incremented modulo 10
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 36 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder after ?nishing a subcode read, the microcontroller must release the interface to allow the decoder to capture new subcode information. this is done by issuing a read to register subcodeqreadend. the availability of a new subcode frame will also trigger an interrupt if interruptenable2 bit subcodereadyenable is set. 6.5.6.3 cd-text interface the channel decoder contains an internal buffer which stores cd-text information (format 4, available in the lead-in area). the buffer can hold one cd-text pack for readback, while at the same time, it receives the next pack. the operation of the cd-text readback interface is controlled via register cdtextcontrol. bit freezeen determines whether or not the internal buffer is frozen during readback (such that the next pack cannot overwrite the current one before the microprocessor has ?nished reading). bit crcfailen determines whether or not packs with a failed crc check are made available for readback. this subcode can be retrieved by the microcontroller, by accessing the registers cdtextstatus, cdtextdata and cdtextreadend. to start retrieving the cd-text pack, the microcontroller must ?rst read the register cdtextstatus. this register contains various status bits that indicate the status of the cd-text pack that may be read. when, after reading the register cdtextstatus, the textready bit is found high, the cdtext interface will be blocked (indicated by textbusy going high) so that no new subcode will overwrite the current one; at least if cdtextcontrol bit freezeen is turned on. textcrcok indicates if the current cd-text pack was indicated correctly, or not, by a hardware crc check. after reading cdtextstatus with textready = '1', the microcontroller may retrieve as many cd-text bytes as required (16 maximum) by issuing subsequent reads to register cdtextdata. after ?nishing cd-text read, the microcontroller must release the interface to allow the decoder to capture new cd-text information. this is done by issuing a read to register cdtextreadend. remark: if cdtextcontrol bit freezeen is disabled, the interface is not held during readback, which means it is possible that the current cd-text pack is overwritten by the next one before all bytes of the current pack are read out. such an event will be indicated by setting cdtextreadend bit bufferoverflow high, so that it can be noticed by software at the end of the pack read. the availability of a new cd-text pack will also trigger an interrupt if interruptenable1 bit cdtextreadyenable) is set. 8 abs min mod100 absolute time 9 abs sec mod 60 10 abs frame mod 75 table 9. q-channel subcode frame content continued address/byte name comments
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 37 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.5.7 main data decoding 6.5.7.1 data processing the cd main data is de-interleaved and error-corrected according to the cd red book (iec 60908) circ decoding standards, and uses an internal sram as buffer and fifo. the c1 correction will correct up to two errors per efm frame, and will ?ag all uncorrectable frames as an erasure. the c2 error correction will correct up to two errors or four erasures, and will also ?ag all uncorrectable frames as an erasure. the decoding operation is controlled by register decomode. there are basically two decode operating modes: ? flush mode: the de-interleaver tables are emptied, and all internal pointers are reset. no data is written into the buffer, no corrections are done, and no data is output ? play mode: de-interleaver tables are ?lled, c1 or c2 corrections are done, and data is output, when available during flush mode, no data is output from the device. during play mode, data is output via the i 2 s interface as soon as it is available in the internal fifo. figure 19 shows the operation of the fifo and corrections during cd playback. de-interleaving of the data is done as required by the cd red book (iec 60908) speci?cation. de-interleaving is performed by the sram fifo address calculation functions in the memory processor. two corrections are done: c1 followed by c2. 6.5.7.2 data latency + fifo operation system data latency is a function of the minimum amount of data required in the fifo to perform the de-interleaving operation. the latency is quoted in the number of c1 frames (24 bytes of user data). the latency of the circ decoder is 118 frames. the fifo ?lling is de?ned as this data latency + the number of extra frames stored in the fifo. the ?lling of the fifo must be maintained within certain limits. 118 frames is the minimum required for de-interleaving, 128 is the physical maximum limit determined by the used sram size. this results in a usable fifo size of 11 frames. the fifo ?lling can be read back via register fifofill. the fifo ?lling must have a correct value. this can be achieved in two ways: fig 19. data processing during cd mode 001aag323 'd' de-interleave data from demodulator to i 2 s back end c1 correction c2 correction fifo fifo filling 'd' de-interleave delta de-interleave
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 38 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder ? master (flow control) mode: selected when using a gated bit clock (bclk) at the i 2 s interface, see section 6.5.9.9 on page 43 for more information. when a frame is available in the fifo, it is output via the i 2 s interface. when fifo under?ow is imminent, the decoder gates the output interface by disabling bclk. ? slave (audio) mode: the bclk is continuously clocked in this mode. the application is responsible for matching the input rate (efm bit rate from the disc) to the selected output rate (i 2 s bclk speed), keeping fifo ?lling between 118 and 128 frames. this is done by regulating the disc speed. see section 6.5.10 for more details. the fifo only stores data, not subcode. this means that the data will be delayed as it comes from the demodulator, but the subcode is sent directly over the i 2 s interface. the difference in delay between subcode and data is always ?xed. it is absolutely ?xed in master mode, but can have small local variations in slave mode. 6.5.7.3 safe and unsafe correction modes the cd circ decoding standard uses a reed-solomon (rs) error correction scheme. reed-solomon error correction has a very small chance of miscorrection, where a corrupted code word is modi?ed into a valid but wrong code word. this results in the code word, after correction, being a valid existing rs code word but not the word that used to be present at this location before corruption. the chance of miscorrections increases exponentially for every extra byte that needs to be corrected in a code word, and is greatest when performing the maximum number of corrections possible with a certain rs correction scheme. miscorrections should be avoided, since they result in corrupted data being sent to the back end, without their corresponding invalid ?ag being set. this is a problem for cd audio, as un?agged wrong data will not get interpolated, which can result in audible clicks. both c1 and c2 correction logic can be programmed to operate in a unsafe or safe mode via register ercocontrol. in unsafe mode, the maximum number of corrections will always be done (if required). in safe mode, corrections will not be done when they are considered too unsafe, which means there is a realistic chance that they could lead to a miscorrection. for c1, unsafe mode allows two bytes per code word to be corrected, safe mode allows only one byte per code word. for c2, both modes will allow up to four erasures per code word to be corrected. when there are more than four erasures, and therefore erco switches back to error correction, unsafe mode allows two bytes to be corrected, safe mode allows only one. remark: from experiments and theory it is advised to use c1 unsafe and c2 safe for cd audio as a good trade-off between safety and maximum error correction capability. for cd-rom, use c1 unsafe and c2 unsafe if there is at least a c3 error correction and if the ?ywheels in the cd-rom block decoder are robust against possible invalid, but not ?agged, headers. 6.5.8 error corrector statistics 6.5.8.1 cflg the error corrector outputs status information on pin cflg. the format of this information is serial and similar to the meas1 signal on pin cl1.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 39 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder the serial format consists of a pause bit followed by a start bit, followed by data bits. the format of the data is explained in t ab le 10 . bit length: seven sysclk periods. frame length: 11 bits. [1] the cflg repetition rate is not ?xed and depends on disc speed and output interface speed. there is always at least one pause bit. [2] cormode de?nition: 000: c1 correction, 011: c2 correction, 100: corrector not active, others: not used. [3] flagfail and corfail indicate failure status on previous code word. [4] errorcount indicates the number of errors found by the error corrector. 6.5.8.2 bler counters there are two bler counters which count the number of frames c1 and c2, with at least one error. c2 erasures coming from c1 are also counted; it is irrelevant if the frame was correctable or not. these registers are reset on read, and the user is responsible for reading them at regular intervals. the bler counters can be read by registers c1bler and c2bler. 6.5.9 audio back end and data output interfaces the channel decoder back end is shown in figure 20 . table 10. format description of cflg serial bus bit value meaning note 0 1 start bit [1] 1 to 3 cormode[2:0] type of correction [2] 4 flagfail failure ?ag set because correction too unsafe [3] 5 corfail failure ?ag set because correction impossible [3] 9, 6 to 8 errorcount[3:0] number of errors corrected [4] 10 0 pause bit [1] fig 20. backend audio functions 001aag324 to i 2 s handler i 2 s left kill right kill interpolate /hold de-emphasis soft mute error detect silence detect kill generation upsample hard mute memory processor ebu interface i 2 s
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 40 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder decoded and error-corrected cd data streams into the back end from the memory processor to the output interfaces; some audio ?ltering can be done in-between, when playing cd-da for example. 6.5.9.1 audio processing the following audio features are present in the back end: ? interpolate/hold for i 2 s ? soft mute for i 2 s ? de-emphasis ?lter for i 2 s ? upsample ?lter for i 2 s ? error detection ? silence detection ? kill generation some status bits concerning these audio features can be read back via register mutekillstatus. 6.5.9.2 interpolate-and-hold on cd audio discs with many large defects, where c1 or c2 correction is unable to correct all the errors, the audio data can be interpolated or held, to avoid audible clicks or plops when playing back the disc. this feature is enabled by setting filtercon?g bit interpolateen. the interpolate-and-hold principle is shown in figure 21 . audio samples ?agged as uncorrectable, neighbored by two good samples, or a held and a good sample, will be interpolated. audio samples ?agged as uncorrectable, which are not followed by a good sample, will hold the previous (correct or held) sample value. this feature is enabled or disabled for i 2 s and ebu together. fig 21. cd audio error concealment 001aag325 ok ok ok ok interpolation hold hold error error error error interpolation
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 41 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.5.9.3 soft mute and error detection the audio data going to the i 2 s and/or ebu interface can be processed by a soft mute block. this block can ramp the audio volume down from 0 db to - 90 db, making use of 64 stages of about - 1.5 db each. the current stage can be monitored and changed by software read or write register mutevolume. this allows the implementation of a software mute scheme. if the hardware mute logic is triggered by the error detection block (explained in the next paragraph), it ramps the volume down from maximum until fully muted in 3 / n ms, where n is the x-rate of the disc. the mute logic can be enabled separately for the i 2 s and ebu outputs, by setting the corresponding bits in register mutecon?g. the back end also contains an error detection block, that scans the data for a programmable number (via register muteondefectdelay) of consecutive corrupted stereo samples. if such a pattern is found, and mutecon?g bit muteerren is turned on, the soft mute will be triggered to start its volume ramp down. this detection will also trigger an interruptstatus1 bit audioerrordetected interrupt. 6.5.9.4 hard mute on ebu the ebu can be hard muted (ebu main data and ?ags set to 0, status and user channel still valid) by setting ebucon?g bit ebuhardmute. 6.5.9.5 silence detection and kill generation the silence detector looks for 250 ms of digital silence (2s complement data = all 1s or all 0s) on either one or both channels and can trigger the kill logic when it is found. this feature is enabled via killcon?g bit killsilenceen. the kill logic generates left and right kill signal outputs from the channel decoder that can be used to gate the left and right channels of an audio dac. the kill signals can be triggered on both channels together by the detection of stereo silence, or on each channel separately by the detection of mono silence. the operation that is active depends on the setting of register killcon?g. it is also possible to set the left and right kill signals by software writing directly to bits killleft and killright in this register. another condition that sets both left and right kill signals is the soft mute block reaching fully muted (volume-stage 0). 6.5.9.6 de-emphasis ?lter this feature only affects the i 2 s, not the ebu output. the de-emphasis ?lter can be used to remove pre-emphasis from tracks which have been recorded using the standard emphasis as described in the cd red book (iec 60908) . the de-emphasis ?lter has the inverse response of the emphasis characteristics as described in the standard.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 42 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder the de-emphasis ?lter is controlled via filtercon?g bit deemphcontrol. the ?lter can be enabled or disabled under software control, or automatically by hardware. in the latter case, the ?lter is turned on when a pre-emphasis bit is detected in the control byte of the q-channel subcode, and turned off when this bit is missing. there are two detection modes possible: ? according to the cd red book (iec 60908) : the pre-emphasis bit is only checked during the lead-in area (allowed to change), and during pauses between tracks ? according to the cd orange book : pre-emphasis is checked on every subcode frame 6.5.9.7 upsample ?lter (four times) this feature only affects the i 2 s, not the ebu output. when it is enabled, the audio data is upsampled by a factor of four. the upsampling provides the frequency response described in t ab le 11 . when upsampling is enabled, the audio data output rate on the i 2 s interface is four times higher than without upsampling. therefore, the i 2 s wclk frequency has to be four times higher. this means the i 2 s bclk speed needs to be programmed to be four times higher than normally required for the x-rate when upsampling would be disabled. fig 22. de-emphasis characteristics 001aag326 t = 50 m s (3.18 khz) t = 15 m s (10.6 khz) frequency gain (db) 0 - 10 table 11. upsample ?lter frequency response passband stop-band attenuation 0 hz to 9 khz - 0.001 db 9 khz to 20 khz - 0.03 db - 24 khz 3 25 db - 24 khz to 27 khz 3 38 db - 27 khz to 35 khz 3 40 db - 35 khz to 64 khz 3 50 db - 64 khz to 68 khz 3 31 db - 68 khz 3 35 db - 69 khz to 88 khz 3 40 db
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 43 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder another result of the upsampling is that every sample will have 18-bit precision after the upsample ?lter instead of 16-bit. to make use of this extra bit precision, the user should select i 2 s-24 of -32 format. when using i 2 s-16 format, the two lowest bits will not be output. 6.5.9.8 data output interfaces there are three interfaces via which data can be output from the channel decoder block. ? i 2 s: main data ? subcode (v4) interface: subcode ? ebu or s/pdif: main data + subcode all interfaces can be used at the same time if needed, although there are a few restrictions on the ebu, see section 6.5.9.10 on page 44 . 6.5.9.9 i 2 s interface the i 2 s is a 6-wire interface (four main + two subcode). it supports 16-bit, 24-bit and 32-bit i 2 s and eiaj (sony) modes. timing is shown in figure 23 . the required format can be selected in register i2sformat. in compliance with the i 2 s speci?cation, i 2 s wclk, i 2 s data, i 2 s ?ag and i 2 s sync are all clocked on the falling edge of i 2 s bclk. ? i 2 s bclk: all other i 2 s signals are clocked on i 2 s bclk ? i 2 s wclk: indicates the start of a new 16- or 18-bit word on the data line, + distinction between left and right sample ? i 2 s data: 16-bit or 18-bit data words are output via this line, 1-bit or bclk period ? i 2 s ?ag: contains the byte reliability ?ag; bytes that are indicated as erasures (possible errors) after c1 and c2 correction, are ?agged ? i 2 s sync: indicates that the serial subcode line (v4) contains the msb of a subcode word; it will be asserted for half a wclk-period after every six wclk-periods. if a subcode sync is transferred on the subcode line, this signal will be asserted for a full wclk period. the i 2 s interface can either work in master or slave mode. in master mode, the i 2 s bclk can be gated off by the channel decoder. in slave mode, the i 2 s bclk is continuously running. to prevent the internal fifo from over?ow, the ?lling of the buffer must be regulated (see section 6.5.7.2 on page 37 ). fig 23. i 2 s format 1 (16 clocks per word) 001aag327 bclk sync data flag wclk d0 d15 d14 d13 d12 d11 d10 d9 flag-msb (1 is unreliable) left right flag-lsb flag-msb d8 d7 d6 d5 d4 d3 d2 d1 d0 d15 d14
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 44 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder i 2 s bclk and i 2 s wclk can either be input (generated outside the channel decoder) or output (generated internally in the clock control block). selection can be done via wclksel and bclksel in register i2scon?g. the i 2 s output rate is determined by the speed of the i 2 s bclk clock, which is con?gured via register bitclockcon?g. one can con?gure the i 2 s interface to run at 1 cd speed or 2 cd speed. for a gated bit clock, when bitclockcon?g bit bclkgen is high, the speed must be con?gured such that the maximum rate available on the bus is 20 % higher than the average data throughput rate i.e. the bus should have at least 20 % idle time between two bursts of data. default after reset, the i 2 s pins on the ic will be put into 3-state. they can be activated via register i2scon?g. this register also contains the possibility to kill the i 2 s interface, such that all data lines output a constant 0. 6.5.9.10 subcode (v4) interface subcode data is output via the i 2 s subo (v4) port. this data can be sampled using the i 2 s sync signal (see section 6.5.9.9 on page 43 ). the sync indicates that the serial subcode line (v4) contains the msb of a subcode word; it will be asserted every six wclk-periods for half a wclk-period. if a subcode sync is transferred on the subcode line, this signal will be asserted for a full wclk period. during normal operation (upsampling disabled), the subcode output via i 2 s subo will have the format as shown in figure 24 . when upsampling is enabled, the i 2 s interface runs at four times the non-upsampled rate. the subcode bit period however will stay at the bit period of the non-upsampled rate as shown in figure 25 . this means that the i 2 s subo and i 2 s sync signal will appear to be four times slower relative to i 2 s wclk. in this case the receiver must use i 2 s wclk divided by 4 to sample the subcode. fig 24. subcode output (upsampling disabled) 001aag328 wclk 1 subcode byte every 24 i 2 s data bytes v4 sync b7 (start) (start) b6 b5 b4 b7 b6 b5 b4 b3 b2 b1 b0
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 45 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder when slave mode is used (no i 2 s bclk gating), it is also possible to use the i 2 s subo (v4) output port as a true single-line interface. in this case the receiver needs to sample the data on the line at a frequency i 2 s wclk 2 (hz) (since subcode is output at a rate of 1-bit or half i 2 s wclk). two characteristics of the interface can be used in this case to synchronize the bit and byte detection in the stream in absence of an i 2 s sync signal. ? the ?rst bit (p-bit) of a subcode byte is used as a start bit and therefore always 1, (no real p-channel information available on the interface); between two subcode bytes there are four zero bits. this can be used to identify the start of the subcode bytes within the stream. ? the subcode syncs s0 and s1 are presented as all zeroes on the interface (even p-channel), such that the last subcode byte of a subcode frame, and the ?rst byte of the next frame are separated by 28 zero bits. this can be used to identify the start of the subcode frames within the stream. 6.5.10 motor a block diagram of the motor interface is given in figure 26 . fig 25. subcode output (upsampling enabled) 001aag329 wclk v4 v4_sync b[7] = start 2 u.s. wclk periods (0.5 non-u.s. wclk period) 24 u.s. wclk periods (6 non-u.s. wclk periods) b[6] s0 s1 b[5] b[7] = start b[6] s0 fig 26. motor servo block diagram 001aag330 0 tacho frequency frequency/tacho set point sw1 g e analog output stage gain - + pll frequency fifo filling m filling set point - + pdm/pwm modulator int k i ki_mult k f kf_mult preset/ read back 24t delay g overflow detect moton pins sw2
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 46 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder the motor servo consists of a pi ?lter and a pwm or pdm modulator. when put in a closed loop, the motor controller can control both speed/frequency and position error (fifo ?ll). it can be operated as a p, i or pi controller, by switching on and off the appropriate switches (sw1, sw2). the frequency and position error integrator gain, k i and k f , and gain g are programmable. frequency and ?lling set points are also programmable. the frequency input source can be selected between pll frequency and zero. the position input source is always fifo ?lling. when operated in a stable operation point in closed loop, the motor controller regulates the frequency input source and the fifo ?lling to their respective set points. this is implemented by speeding up or slowing down the motor by changing the dc content in the pdm/pwm output motor signals. all parameters can be con?gured by programming the motor registers. 6.5.10.1 frequency setpoint when operating the motor in clv mode, based on efm, for a certain overspeed, the motor frequency set point to be programmed is given by: (6) where f clk(sys) is the system clock frequency and n is the overspeed factor. the set point can be programmed via register motorfreqset. the selection of the motor frequency input is programmed via motorgainset2 bit motorfreqsource. 6.5.10.2 position error the position error will be used to ?ne tune the motor speed during slave mode where the incoming efm bit rate is locked on the programmed ?xed i 2 s bclk output speed. the set point must be chosen between 118 and 128, since this is the usable fifo size in the decoder. for more information, see section 6.5.7.2 on page 37 . the set point can be programmed via register motorfifoset. 6.5.10.3 motor control loop gains (k p , k f and k i ) the motor control loop gains are all programmable, through registers motorgainset1 and motorgainset2. to be able to set integrator bandwidth low enough at high system clock speeds, an extra divider for the factors k i and k f is added. these factors can be written through the register motormultiplier. the resulting k i(tot) is then the k i multiplied by ki_mult. the resulting k f(tot) is then the k f multiplied by kf_mult. the integrator bandwidth must be scaled with the same factor ki_mult. notes: motorfreqset [7:0] 256 1 n 4.3218 6 10 2.667 f clk sys () --------------------------------------- - C ? ? ?? =
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 47 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder ? kf_mult operates by sampling the input. for example, for kf_mult = 1, every sample of the input is passed through to the integrator circuit, for a kf_mult of 0.5, every second sample is passed through, for a kf_mult of 0.25, every fourth sample is passed through, and so on. ? for a dc input signal, k f kf_mult should always give the same result. if however, the input is varying quickly, the k f kf_mult combinations with the same product will not always give the same result, especially for low values of kf_mult, where the sampling in the extreme becomes 1 out of every 128 samples. the input samples to the block that performs the kf_mult multiplication occur at a rate of one sample every 24 system clock periods. sub-sampling might affect the resulting gain. 6.5.10.4 operation modes the motor controller mode is programmed in register motorcontrol. it can operate open loop, just sending a ?xed power to the motor, for start-up and stopping, closed loop, or shut-down. this register also selects between pdm and pwm formats. motor start and stop modes will put a ?xed duty cycle pwm or ?xed density pdm signal on the motor outputs. during start or stop, motor speed can be monitored by reading motorintlsb and motorintmsb. motorov: when not setting the appropriate gains in the loop, an over?ow might occur inside the pwm/pdm modulator block, or in the programmable gain stage. this is signalled by the motorov interrupt, which can be read back on interruptstatus2. the interrupt clears when the over?ow clears. motorov can also automatically open sw1 or sw2. this is enabled by writing a 1 to bit ovfsw in register motorcontrol. 6.5.10.5 writing, reading motor integrator value it is possible to obtain the integrator value by reading the registers motorintlsb and motorintmsb. the integrator can be written at the same location. by opening all switches, the user can bypass the whole control and ?lter part, and just use the block as a dac towards the motor drivers. the control part can then be done by software. 6.5.10.6 some notes on application motor servo the motor servo can be used to control the motor during clv playback and also during cav or pseudo-clv lock-to-disc or jump mode. ? in clv mode, both sw1 and sw2 must be closed ? in cav/pseudo-clv mode, sw2 must be open and sw1 can be open ? the motor servo will revolve the disc at the speed corresponding to the frequency set point. in clv mode with lock to efm, the frequency set point must be selected equal to the desired readout frequency of the hf pll ? accelerating the disc must be done in one of the start modes ? braking the disc must be done in one of the stop modes
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 48 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.5.10.7 tacho the tacho circuit accepts the tacho input on the tacho inputs t1, t2 and t3, coming from the hall sensors on the spindle motor. the tacho block measures the frequency of the input pulses, and ?lters the measurements using a second-order low-pass ?lter to remove noise on the tacho signal. the measured tacho frequency can be read by the microprocessor, and can be used as a frequency input to the motor control, and can be used to generate the tacho trip frequency interrupt. the relationship between the actual motor speed (in hz) and the tachofrequency[7:0] value read back in register tacho4, bit tachofrequency is given by: (7) where: ? tachofrequency[7:0] is the value read from register tacho4; when doing cav mode motor control, it is compared to the motor frequency set point programmed in register motorfreqset - an unsigned value ? motorfreq is the angular velocity in rounds per second (hz) ? ktacho[7:0] is the gain value written to register tacho1 ? 2h: h is the number of hall sensors: 1 or 3, depending on motor and setting of bit onepinmode in register tacho3 ? p is the number of motor pole-pairs, usually 1 ? f s is the sampling frequency of the ?lter; this can be con?gured via bit fsamsel in register tacho4 tacho gain ktacho: the tacho gain, ktacho[7:0] can be chosen so that the value read from bit tachofrequency in register tacho2 is the motor frequency in hz. however, it is advisable to select ktacho[7:0] such that a minimum amount of ripple is seen on the measured tacho frequency. this must be tuned experimentally. tests have shown that with good selection of ktacho[7:0] and tachosamplerate, a minimum amount of variation on the measured frequency can be obtained. fig 27. tacho block diagram 001aag331 transition detect + debounce compare to motor loop tacho set ktacho tacho interrupt t1 t2 t3 3 tachofrequency 7:0 [] motorfreq k tacho 7:0 [] 2h p f s ------------------------------------------------------------------------------------------ =
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 49 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder tacho trip frequency: it is possible for the software to be noti?ed with an interrupt when reaching a speci?c speed during spin-up or spin-down. this is done by programming the desired frequency trip point in register tacho2. when the tacho frequency goes above or below this trip point, an interrupt gets generated (bit 3 of register interruptstatus2). bit 1 (tachointerruptselect) of register tacho3 can be set to enable an interrupt to be generated when the frequency goes above or below the trip point. 6.6 parallel digital servo ic (pdsic) the digital servo block design on the saf784x has evolved from the design used on the saa7824 ic, and is referred to as the pdsic. parallel, refers to the microprocessor interface of the servo block which is now a high speed parallel interface. previously, it was a serial interface used on the saa7824, 3 or 4-wire, i 2 c-bus. the pdsic features are listed below: ? programmable adc for cd-rw playback compatibility ? diode signal processing ? signal conditioning ? focus and radial control system ? access control ? sledge control ? shock detector ? defect detector ? off-track counting and detection ? automatic closed-loop gain control available for focus and radial loops ? hi-level features ? flexible servo 6.6.1 pdsic registers and servo ram control the servo block is controlled by two parts of the design: the servo control registers which are used to control the writing of commands and parameters to the servo, and the servo ram. the servo ram has two roles: storage of the servo parameters, and capture of commands and parameters during the command process. all of the servo write commands consist of a command byte followed by a number of parameter bytes (between one and seven), all of which have to be loaded into the pdsic using a serial communication interface. the command byte is the ?rst to be loaded and can be considered as two nibbles. the upper (most signi?cant) nibble represents the command itself whilst the lower (least signi?cant) nibble tells the pdsic how many parameter bytes to expect. the command byte gets placed into memory location 0x31 (called oldcom). subsequently, parameter bytes get loaded sequentially and these get placed into a stack space that has been reserved within the memory (locations 0x30 down to 0x2b). with each parameter byte that is loaded, the value in oldcom is decremented so that the byte count decreases to zero, and the pdsic knows it has a complete servo command (a
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 50 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder command byte and its full compliment of parameter bytes). at this point, the pdsic acts upon the command and the appropriate function is carried out based upon the values in the stack space. there are two special case servo commands: write_parameter (opcode = 0xa2) and write_decoder_reg (opcode = 0xd1). write_parameter allows the microcontroller to write directly to any memory location. it carries two parameter bytes: the memory address and the data that is to be written. when this command is executed, the command byte is loaded into oldcom and the ?rst parameter byte (ram_address) is loaded in the stack. the second parameter byte (data) is loaded directly to the location speci?ed by the ram_address. write_decoder_reg allows decoder registers to be written to when the i 2 c-bus interface is being used. this command carries only one parameter byte, which is the decoder register/data pair (two nibbles). when this command is received by the pdsic, the register/data pair is loaded into memory location 0x4d. the servo read commands operate slightly differently because they carry no parameter bytes and the lower nibble of the command byte is always 0 to indicate this. when the pdsic receives a read command, it will make certain information available (mostly from memory, although some status information is retrieved from the decoder) on the serial interface for collection by the microcontroller. if a sequence of values is being read from the servo ram (e.g. a series of values related to a pid loop), it is important to ensure that the values are consistent with each other by ensuring that the servo has not updated some of the values during the period that they are being read. to prevent this occurring, an interrupt signal is available from the servo to the arm which asserts an irq when it is safe to read related values. the interrupt generator monitors these signals and raises an irq whenever the correct state is achieved. the interrupt is cleared by applying a pulse to the inreq_clr register bit. if the interrupt is not cleared, it will automatically be reset when the valid reading state is no longer true. figure 28 shows the operation of the irq signal. int #1 shows the full duration of an interrupt that does not get cleared by the arm. int #2 and int #3 are shown being cleared by pulses being written to the inreq_clr register. the time between interrupts is approximately 15 m s and the total interrupt cycle time is about 60 m s.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 51 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder the saf784x contains additional circuits to implement a servo feature called flexi servo. the purpose of the ?exible servo system is, in conjunction with the existing analog and digital lf path, to provide maximum ?exibility in the use of the entire servo loop. this scheme extends from the point of diode pdm generation at the analog adc outputs through to the servo actuator signals (ra, fo and sl) themselves. from a system perspective, the simplest con?guration provides an lf path that is equivalent to the hardware servo (pdsic) of the other audio devices such as saa7826, which uses the on-board hardware servo controller logic. however, an alternative setup will provide additional ?ne dc-offset compensation (in addition to the coarse compensation already found in the analog adcs) and the potential for full software servo control via the arm microprocessor. full system con?guration details are given in the block diagrams in the sections below. 6.6.2 diode signal processing the photo detector in conventional two-stage three-beam compact disc systems normally contains six discrete diodes. four of these diodes (three for single foucault systems) carry the central aperture signal (ca) while the other two diodes (satellite diodes) carry the radial tracking information. the ca signals are summed into an hf signal for the decoder function and are also differenced (after a-d conversion) to produce the low frequency focus control signals. the low frequency content of the six (?ve if single foucault) photodiode inputs are converted to pulse-density modulated bit streams by a multiplexed 6-bit adc followed by a digital pdm generation circuit. this supports a range of opus in voltage mode mechanisms by having sixteen selectable gain ranges in two sets, one set for d1 to d4 and the other for r1 and r2. fig 28. function of servo irq signal with respect to srv_fc0, srv_fc1 and inreq_clr 001aag332 irq cycle time of ~60 m s natural duration of irq (~45 m s) srv_fc0 srv_fc1 irq inreq_clr irq #2 cleared by inreq_clr pulse irq #3 cleared by inreq_clr pulse int #1 int #2 int #3 irq cycle time of ~60 m s irq cycle time of ~60 m s
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 52 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.6.3 signal conditioning the digital codes retrieved from the adc and pdm generator are applied to logic circuitry to obtain the various control signals. the signals from the central aperture diodes are processed to obtain a normalized focus error signal. (8) where the detector setup is assumed to be as shown in figure 29 . for the single foucault focusing method, the signal conditioning can be switched under software control such that the signal processing is as follows: (9) the error signal, fe n , is further processed by a proportional-integral and differential (pid) ?lter section. an internal ?ag is generated by means of the central aperture signal and an adjustable reference level. this signal is used to provide extra protection for the track loss (tl) generation, the focus start-up procedure and the dropout detection. the radial or tracking error signal is generated by the satellite detector signals r1 and r2. the radial error signal can be formulated as follows: re s = (r1 - r2) re_gain + (r1 + r2) re_offset where the index s indicates the automatic scaling operation which is performed on the radial error signal. this scaling is necessary to avoid non-optimum dynamic range usage in the digital representation and reduces the radial bandwidth spread. furthermore, the radial error signal will be made free from offset during start-up of the disc. the four signals from the central aperture detectors, together with the satellite detector signals generate a track position indicator signal (tpi) which can be formulated as follows: tpi = sign [(d1 + d2 + d3 + d4) - (r1 + r2) sum_gain] where the weighting factor sum_gain is generated internally by the saf784x during initialization. fe n d1 d2 C d1 d2 + --------------------- d3 d4 C d3 d4 + --------------------- C = fe n 2 d1 d2 C d1 d2 + --------------------- =
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 53 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.6.4 focus servo system 6.6.4.1 focus start-up the start-up behavior of the focus controller is in?uenced by ?ve initially loaded coef?cients. the automatically-generated triangular voltage can be in?uenced by three parameters: height (ramp_height), dc offset (ramp_offset) of the triangle, and its steepness (ramp_incr). for protection against detection of false focus points, two parameters are available which are an absolute level on the ca signal (ca_start) and a level on the fe n signal (fe_start). focus is achieved when this ca level is reached. when focus is achieved and the level on the fe n signal is reached, the focus pid is enabled to switch on when the next zero crossing is detected in the fe n signal. 6.6.4.2 focus position control loop the focus control loop contains a digital pid controller which has ?ve parameters available to the user. these coef?cients in?uence integrating (foc_int), proportional (foc_lead_length, part of foc_parm3) and differentiating (foc_pole_lead, part of foc_parm1) action of the pid and a digital low-pass ?lter (foc_pole_noise, part of foc_parm2) following the pid. the ?fth coef?cient, foc_gain in?uences the loop gain. figure 30 shows the transfer function of the controller, and the coef?cients which determine its behavior. fig 29. detector arrangement 001aag333 d1 d3 d2 d4 satellite diode r1 satellite diode r2 d1 d2 d3 d4 satellite diode r1 satellite diode r2 d1 d2 d3 satellite diode r1 satellite diode r2 astigmatic focus double foucault single foucault
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 54 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder a simpli?ed block diagram of the focus pid system is given in figure 31 . the actuator position can be held by using a zero error signal. this action is taken if a defect or shock is encountered. the pid is followed by a low-pass ?lter to reduce audible noise in the control loop. the desired frequencies for the loop ( w 1 to w 4 ) are used to calculate the coef?cient values (full tables are given in the hsi). an explanation of the different parameters in these diagrams is given in t ab le 12 . fig 30. bode diagram of focus pid system fig 31. block diagram of focus pid system table 12. focus pid parameters parameter controlled by comment w 1 - focus integrator bandwidth w 2 - start of focus lead w 3 foc_parm1 foc_pole_lead; end of focus lead (differentiating part) w 4 foc_parm2 foc_pole_noise; low-pass function following pid w 3 / w 2 foc_parm3 foc_lead_length; lead length (proportional part) w 1 = ( w 5 w 3 / w 2 ) foc_int_strength integrator strength g foc_gain focus loop gain g e end stage gain de?ned as peak-to-peak voltage swing over focus actuator 001aag334 frequency (log hz) amplitude (db) foc_gain foc_int_strength w 5 w 1 w 2 w 3 w 4 id p foc_lead_length foc_int foc_pole_noise foc_pole_lead 001aag335 1 / j w j w / w 3 1 + j w / w 3 w 1 w 2 / w 3 w 4 focus error, fe n p internal external d g focus actuator g e i zero on defect or shock
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 55 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.6.4.3 dropout detection this detector can be in?uenced by one parameter (ca_drop). focus will be lost and the integrator of the pid will hold if the ca signal drops below this programmable absolute ca level. when focus is lost it is assumed, initially, to be caused by a black dot. 6.6.4.4 focus loss detection and fast restart whenever focus is lost for longer than approximately 3 ms, it is assumed that the focus point is lost. a fast restart procedure is initiated which is capable of restarting the focus loop within 200 ms to 300 ms depending on the programmed coef?cients of the microcontroller. 6.6.4.5 focus loop gain switching the gain of the focus control loop (foc_gain) can be multiplied by a factor of 2 or divided by a factor of 2 during normal operation. the integrator value of the pid is corrected accordingly. the differentiating (foc_pole_lead) action of the pid can be switched at the same time as the gain switching is performed. 6.6.4.6 focus automatic gain control loop the loop gain of the focus control loop can be corrected automatically to eliminate tolerances in the focus loop. this gain control injects a signal into the loop which is used to correct the loop gain. since this decreases the optimum performance, the gain control should only be activated for a short time (for example, when starting a new disc). 6.6.5 radial servo system 6.6.5.1 radial pid - on-track mode when the radial servo is in on-track mode (normal play mode), a pid controller is active for the fast actuator, while the sledge is steered using either a pi or pulsed-mode system. a simpli?ed diagram of the radial pid system is given in figure 32 . an explanation of the different radial pid parameters are given in t ab le 13 . the system frequency response is given in figure 33 . fig 32. block diagram of radial pid system 001aag343 j w / w 3 1 + j w / w 3 w 4 scaled radial error satellite 1 satellite 2 internal sledge error signal external i p g radial actuator g e d zero on defect or drop out 1 / j w w 1 w 2 / w 3 normalizer
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 56 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.6.5.2 level initialization during startup, an automatic adjustment procedure is activated to set the values of the radial error gain (re_gain), offset (re_offset) and satellite sum gain (sum_gain) for tpi level generation. the initialization procedure runs in a radial open loop situation and is 300 ms. this start-up time period may coincide with the last part of the motor start-up time period: ? automatic gain adjustment: as a result of this initialization the amplitude of the re signal is adjusted to within 10 % around the nominal re amplitude ? offset adjustment: the additional offset in re due to the limited accuracy of the start-up procedure is less than 50 nm tpi level generation: the accuracy of the initialization procedure is such that the duty factor range of tpi becomes 0.4 < duty factor < 0.6 (default duty factor = tpi high / tpi period). 6.6.5.3 dropout detection this detector can be in?uenced by one parameter (ca_drop). focus will be lost and the integrator of the pid will hold if the ca signal drops below this programmable absolute ca level. when focus is lost, it is assumed initially, to be caused by a black dot. table 13. radial pid parameters parameter controlled by comment w 1 - radial integrator bandwidth w 2 - start of radial lead w 3 rad_parm_play end of radial lead (differentiating part) w 4 rad_pole_noise low-pass function following pid w 3 / w 2 rad_length_lead lead length (proportional part) w 5 = ( w 1 w 2 / w 3 ) rad_int_strength integrator strength g rad_gain radial loop gain g e end stage gain de?ned as peak-to-peak voltage-swing over radial actuator fig 33. bode diagram of radial pid system 001aag344 frequency (log hz) amplitude (db) rad_gain rad_int_strength w 5 w 1 w 2 w 3 w 4 id p rad_lead_length rad_int rad_pole_noise rad_pole_lead
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 57 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.6.5.4 focus loss detection and fast restart whenever focus is lost for longer than approximately 3 ms it is assumed that the focus point is lost. a fast restart procedure is initiated which is capable of restarting the focus loop within 200 ms to 300 ms depending on the programmed coef?cients of the microcontroller. 6.6.5.5 focus loop gain switching the gain of the focus control loop (foc_gain) can be multiplied by a factor of 2 or divided by a factor of 2 during normal operation. the integrator value of the pid is corrected accordingly. the differentiating (foc_pole_lead) action of the pid can be switched at the same time as the gain switching is performed. 6.6.5.6 focus automatic gain control loop the loop gain of the focus control loop can be corrected automatically to eliminate tolerances in the focus loop. this gain control injects a signal into the loop which is used to correct the loop gain. since this decreases the optimum performance, the gain control should only be activated for a short time (for example, when starting a new disc). 6.6.6 radial servo system 6.6.6.1 level initialization during startup, an automatic adjustment procedure is activated to set the values of the radial error gain (re_gain), offset (re_offset) and satellite sum gain (sum_gain) for tpi level generation. the initialization procedure runs in a radial open-loop situation and is 300 ms. this start-up time period may coincide with the last part of the motor start-up time period: ? automatic gain adjustment: as a result of this initialization the amplitude of the re signal is adjusted to within 10 % around the nominal re amplitude ? offset adjustment: the additional offset in re due to the limited accuracy of the start-up procedure is less than 50 nm ? tpi level generation: the accuracy of the initialization procedure is such that the duty factor range of tpi becomes 0.4 < duty factor < 0.6 (default duty factor = tpi high / tpi period) 6.6.6.2 sledge control the microcontroller can move the sledge in both directions via the steer sledge command. 6.6.6.3 tracking control the actuator is controlled using a pid loop ?lter with user-de?ned coef?cients and gain. for stable operation between the tracks, the s-curve is extended over 0.75 of the track. on request from the microcontroller, s-curve extension over 2.25 tracks is used, automatically changing to access control when exceeding those 2.25 tracks. both modes of s-curve extension make use of a track-count mechanism. in this mode, track counting results in an automatic return-to-zero track to avoid major disturbances in the audio output and providing improved shock resistance. the sledge is continuously controlled, or provided with step pulses to reduce power consumption using the ?ltered value of the radial pid output. alternatively, the microcontroller can read the average
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 58 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder voltage on the radial actuator and provide the sledge with step pulses to reduce power consumption. filter coef?cients of the continuous sledge control can be preset by the user. 6.6.6.4 access the access procedure is divided into two different modes depending on the requested jump size; see t ab le 14 . [1] microcontroller presettable. the access procedure makes use of a track-counting mechanism, a velocity signal based on a ?xed number of tracks passed within a ?xed time interval, a velocity set point calculated from the number of tracks remaining, and a user-programmable parameter indicating the maximum sledge performance. if the number of tracks remaining is greater than the brake_distance then the sledge jump mode should be activated, or the actuator jump should be performed. the requested jump size together with the required sledge breaking distance at maximum access speed de?nes the brake_distance value. during the actuator jump mode, velocity control with a pi controller is used for the actuator. the sledge is then continuously controlled using the ?ltered value of the radial pid output. all ?lter parameters (for actuator and sledge) are user programmable. in the sledge jump mode, maximum power (user programmable) is applied to the sledge in the correct direction while the actuator becomes idle (the contents of the actuator integrator charge current reduces to zero just after the sledge jump mode is initiated). the actuator can be electronically damped during sledge jump. the gain of the damping loop is controlled via the hold_mult parameter. the fast track jumping circuitry can be enabled or disabled via parameter xtra_preset. 6.6.6.5 radial automatic gain control loop the loop gain of the radial control loop can be corrected automatically to eliminate tolerances in the radial loop. this gain control injects a signal into the loop which is used to correct the loop gain. since this decreases the optimum performance, the gain control should only be activated for a short time (for example, when starting a new disc). this gain control differs from the level initialization. the level initialization should be performed ?rst. the disadvantage of using the level initialization without the gain control is that only tolerances from the front end are reduced. 6.6.7 off-track counting the track position indicator (tpi) signal is a ?ag which is used to indicate whether the radial spot is positioned on the track, with a margin of 1 4 of the track-pitch. in combination with the radial polarity (rp) ?ag the relative spot position over the tracks can be determined. table 14. radial servo access procedure modes access type jump size access speed actuator jump brake_distance [1] decreasing velocity sledge jump brake_distance - 32768 maximum power to sledge [1]
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 59 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder these signals can have uncertainties caused by: ? disc defects such as scratches and ?ngerprints ? the hf information on the disc; which is considered as noise by the detector signals in order to determine the spot position with suf?cient accuracy, extra conditions are necessary to generate a track loss (tl) signal and an off-track counter value. these extra conditions in?uence the maximum speed and this implies that, internally, one of the following three counting states is selected: ? protected state: used in normal play situations; a good protection against false detection caused by disc defects is important in this state. ? slow counting state: used in low-velocity track jump situations; in this state a fast response is important rather than the protection against disc defects (if the phase relationship between tl and rp of 1 2 p radians is affected too much, the direction cannot then be determined accurately). ? fast counting state: used in high-velocity track jump situations; highest obtainable velocity is the most important feature in this state. 6.6.8 defect detection a defect detection circuit is incorporated into the saf784x. if a defect is detected, the radial and focus error signals may be zeroed, resulting in better playability. the defect detector can be switched off, applied only to focus control or applied to both focus and radial controls under software control (part of foc_parm1). the defect detector has programmable set points selectable by the parameter defect_parm. 6.6.9 off-track detection during active radial tracking, off-track detection is realized by continuously monitoring the off-track counter value. the off-track ?ag becomes valid whenever the off-track counter value is not equal to zero. depending on the type of extended s-curve, the off-track counter is reset after 0.75 track extend mode, or at the original track in the 2.25 track extend mode. 6.6.10 high level features 6.6.10.1 automatic error handling three watchdogs are present: ? focus: detects focus dropout of longer than 3 ms, sets focus lost interrupt, switches off radial and sledge servos, and disables drive to disc motor fig 34. defect detector block diagram 001aag345 decimation filter defect generation fast filter slow filter programmable hold-off defect output satellite 1 satellite 2 - +
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 60 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder ? radial play: started when radial servo is in on-track mode and a ?rst subcode frame is found; detects when maximum time between two subcode frames exceeds the time set by the playwatchtime parameter; then sets radial error interrupt, switches radial and sledge servos off, and puts disc motor in jump mode ? radial jump: active when radial servo is in long jump or short jump modes; detects when the off-track counter value decreases by less than four tracks between two readings (time interval set by jumpwatchtime parameter); then sets radial jump error, switches radial and sledge servos off to cancel jump the focus watchdog is always active, the radial watchdogs are selectable via parameter radcontrol. 6.6.10.2 automatic sequencers and timer interrupts two automatic sequencers are implemented (and must be initialized after power-on): ? auto-start sequencer: controls the start-up of focus, radial and motor ? auto-stop sequencer: brakes the disc and shuts down servos when the automatic sequencers are not used it is possible to generate timer interrupts, de?ned by the time_parameter coef?cient. 6.6.11 driver interface the control signals (pins ra, fo and sl) for the mechanism actuators are pulse-density modulated. the modulating frequency can be set to either 1.0584 mhz or 2.1168 mhz, controlled via parameter xtra_preset. an analog representation of the output signals can be achieved by connecting a 1st-order low-pass ?lter to the outputs. during reset ( reset pin is held low) the ra, fo, and sl pins are high impedance. at all other times, when the laser is switched off, the ra and fo pins output a 2 mhz 50 % duty-cycle signal. 6.7 flexi servo options the flexi servo contains some additional hardware: ? lpf : the low-pass ?lters construct a multi-bit representation of the incoming pdm stream arriving from the analog adcs; the cut-off frequencies of all the ?lters are user-programmable from registers. ? fine dc-offset subtraction : the ?ne dc-offset values are held in cd-slim registers; these values can be subtracted from the lpf outputs. ? decimation ?lter : the decimation ?lter behavior is controlled by the lpf cut-off frequency selection and passes only the n th sample. ? interrupt generator : this block raises an interrupt every time the output of the decimation ?lter becomes valid; the interrupt will either clear itself after a given time or can be cleared by the arm microprocessor. ? servo registers : registers that exist within the servo register address range; depending upon their function they will be either read-only or write/read registers; some of the ?exible servo registers utilize the full 32-bits available to improve bandwidth performance for certain ?exible servo operations.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 61 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder ? sigma-delta noise shaper : this block regenerates a pdm data stream from a given multi-bit value, which is provided at its inputs. 6.7.1 modes of operation the ?exible servo can be used in six main modes, they are described in the following sections. 6.7.1.1 hardware servo-only this mode uses the hardware servo (pdsic) only without any additional processing taking place on either the diode input signals or the servo output signals. 6.7.1.2 hardware servo with ?ne offset compensation this mode is the same as hardware servo-only mode but has the addition of the ?ne offset compensation functionality in the digital domain. the ?ne offset compensation is additional to the coarse offset compensation, which is available in all ?exible servo modes. 6.7.1.3 fully ?exible servo also known as software servo. the diode signals have the ?ne offset applied to them and are passed to registers for reading by the arm microprocessor. the complete servo functionality is implemented in software running on the arm; the pdsic hardware servo is switched out of the loop entirely. the arm calculates values, which are used to generate servo signals for driving the mechanism actuators. the pdm generation for the servo output signals is performed by the sigma-delta block. 6.7.1.4 pre-processing with hardware servo the diode signals have the ?ne offset applied to them and are passed to registers for reading by the arm microprocessor. the arm pre-processes these signals and they are fed back to the inputs of the hardware servo via sigma-delta noise shapers. the hardware servo (pdsic) performs all the control functions (on the modi?ed input signals) and outputs the servo signals as hardware servo-only mode. 6.7.1.5 hardware servo with post-processing the diode signals are passed directly to the hardware servo inputs (can be with, or without, ?ne-offset compensation added). the pdsic servo output signals are passed to registers for reading by the arm microprocessor. the arm executes any post-processing it deems necessary on the signals and passes new values back which are used to drive the mechanism actuators. the servo outputs are therefore generated by the arm, rather than the pdsic, but based on the signals provided by the pdsic. 6.7.1.6 pre-processing with hardware servo plus post-processing the diode signals have the ?ne offset applied to them and are passed to registers for reading by the arm microprocessor. the arm pre-processes these signals and they are fed back to the inputs of the hardware servo via sigma-delta noise shapers. the hardware servo performs all the control, and the servo output signals are passed to registers for reading by the arm microprocessor. the arm executes any post-processing it deems necessary on the signals and passes new values back which are used to drive the mechanism.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 62 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.8 block decoder the general features of the saf784x block decoder are: ? 32-bit microprocessor interface ? channel decoder compatible c2i interface ? segmentation manager compatible mimed2 interface the main cd decode features of the saf784x block decoder are: ? 16-bit data channel ? data byte swapping ? sync pattern (0x00, 0xff to 0xff, 0x00) detection and interpolation ? main data de-scrambling (as per the cd yellow book (iso/iec 10149) for mode 1, mode 2 form 1 and mode 2 form 2 sectors) ? header (msf address) monitoring, interpolation and repair ? firmware programmable 1-bit stream ?ltering on sector boundaries (cd-rom only) ? fast real-time c3 error correction (including automatic detection of mode 1, mode 2 form 1, and mode 2 form-2 sectors) using an internal two sector sram ? separate 8-bit subcode channel ? subcode p + q channel de-interleaving and q channel crc checking ? subcode cd-text mode four-packet extraction and crc checking ? automatic subcode stream ?ltering associated with the data stream ?lter ? stream building (the main data stream, the block error byte, the error ?ag bytes and the subcode channel will be merged into a single data stream for transmission to the segment manager ? status word tag creation (which contains sector-speci?c information)
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 63 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.8.1 supported modes of operation the block decoder supports cd-da and cd-rom decode transfers. cd main data and subcode data are received from cd-slim over the c2i interface. the main data is processed by the decode main data path functions before being passed to the memory controller. in the memory controller the main data is assimilated with the subcode data and the c3 error corrector is run on cd-rom main data. the sector data and some status information are then passed to the saf784x segment manager over the mimed2 interface. 6.8.2 channel decoder to block decoder interface (c2i) the data interface between the channel decoder and the block decoder is an asynchronous interface; the channel decoder and the block decoder operate in independent clock domains. data is transferred over c2i in bursts of one efm frame. each efm frame consists of one subcode data byte plus twelve 16-bit main data words with associated reliability ?ags. cd-rom data is word-aligned as per the cd yellow book (iso/iec 10149) with the ?rst word of the cd-rom sync pattern appearing on a left audio word. the subcode sync may, or may not, be aligned with the ?rst word of the cd-rom sync pattern depending on the alignment on the disc. subcode data is provided at the rate of one byte per efm frame. each byte contains a bit for each of the subcode channels, p-w (p channel is bit 7). fig 35. block decoder data path 001aag346 ahb bus c2i silicon debug bus mimed2 arm ahb register interface cd-rom sync detector channel decoder interface cd subcode data path segmentation manager interface cd main data cd subcode data cd subcode data sector sync flywheel decode main data path cd main data cd-rom msf flywheel stream filter (start/stop) cd memory controller sram cd-rom de-scrambler cd-rom c3 error corrector cd-rom main data cd data silicon debug bus interface (block verification) read/write/debug debug
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 64 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder the alignment between the main channel and the subcode channel must be the same each time a sector is read. 6.8.3 block decoder to segmentation manager interface the mimed2 interface is the data interface between the block decoder and the saf784x segment manager. it is an asynchronous interface; the block decoder and saf784x segment manager operate in independent clock domains. data is transferred over mimed2 in bursts of one sector. the size and speed of the transfer is determined by the settings in the op_ctrl register. each transaction on mimed2 is accompanied by a toggle of the bld_req signal. the data and ?ags are updated on each transaction. the transfer order is: 1. main data: 1176 word16 (2352 bytes) 2. flags data (optional): 148 word16 (296 bytes) 3. subcode data (optional): 57 word16 (114 bytes) 4. status words: two word16 (four bytes) 6.9 segmentation manager 6.9.1 general the segmentation manager controls the ?ow of block-decoded data from the block decoder and synchronous arm system bus. the segmentation manager consists of a 2 kb buffer, that is accessible on the arm subsystem bus once the entire sector has been transferred from block decoder into the segmentation buffer. the dma cycle is then initiated to transfer sector data from the segmentation manager to the arm processor memory for mp3 decoding to commence. the dma transfers are expected to be continuous burst transfers to arm processor memory and completed at the sector boundary. the segmentation manager register sel_write_mode allows access to the segmentation buffer either to the block decoder mimed interface or the synchronous arm system bus. remark: access to segmentation buffer from the mimed interface is write access only, or access only from synchronous arm processor system bus is read access only. the segmentation buffer memory is 692-bit sram 32-bit sram. the maximum number of 32-bit words per complete sector is 692 words. 6.9.2 interrupt generation an interrupt is generated on completion of transfer of every sector from the block decoder. the signal memory_full is used to generate an interrupt. the interrupt, once serviced by software, can be cleared by register write to inreq_clr.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 65 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder once the interrupt has been triggered, it will remain asserted until cleared by the inreq_clr signal. however, after being cleared, it is then free to ?re again on the next transition. note that the register bit inreq_clr retains the latest value written by the arm processor so a typical sequence will be to write logic 0 followed some time later by logic 1 in order to return to the non-reset state. 6.9.3 segmentation buffer arm sub-system interface the segmentation buffer access to the arm sub-system is fully synchronous. the implementation allows for minimum latency-overhead so as to maximize the available bandwidth on the arm processor. the synchronous interface is amba ahb-compliant. note: the synchronous transfers are initiated by the direct memory access (dma) controller. once sector transfer has been initiated, the recommendation is that these transfers should not be interrupted and the application must allow for the complete sector to be copied to the main arm sub-system 110 kb internal memory. fig 36. saf784x data path with segmentation manager 001aag347 arm7tdmi-s (master) ahb synchronous interface mimed2 dma master multi-layer ahb bus 16 15 32 32 32 c2i cd slim block decoder ahb rom acu arbitration interrupt handling segmentation memory segmentation manager ahb ram i 2 s handler src dem dac
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 66 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 6.10 laser interface the laser diode pre-amp function is built in to the saf784x and is illustrated in figure 37 . the current, up to 120 ma, can be regulated in four steps ranging from 58 % up to full power. the voltage derived from the monitor diode is maintained at a steady state by the laser drive circuitry, regulating the current through the laser diode. 7. arm7 system the following sections give a top-level description of the individual blocks. 7.1 arm7tdmi-s microprocessor the arm7tdmi-s microprocessor is a member of the arm family of 32-bit processors. the arm processor offers a high performance with low power consumption and low gate count. the arm architecture is based upon risc. the risc principles provide the following key bene?ts: ? high instruction throughput ? excellent real-time interrupt response fig 37. block diagram of laser control circuit laser power vmon_dac laser_comp_out 001aag348 up/down counter timing and control logic laser diode & monitor pin monitor pin laser laser_ion pin lpower laser_pdmin dac laser_dk8mhz laser_dk32mhz dac comparator
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 67 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder [1] the frequency of operation depends on the performance required for the saa7834 application and the software complexity. mp3/wma decoding requires most high-speed peripherals to operate at this frequency. the mp3/wma decoding library is implemented in software. the arm7tdmi-s processor has two instruction sets: 1. the 32-bit arm instruction set 2. the 16-bit arm thumb instruction the arm uses a three-stage pipeline to increase the throughput of the ?ow of instructions to the processor. this enables several operations to operate simultaneously and the processor and memory systems to operate continuously. the three-stage pipelines can be de?ned in the following stages: ? fetch cycle: fetches the instruction from the memory ? decode cycle: decodes the registers and the instructions fetched ? execute cycle: fetches the data from register banks; the shift, alu operations performed and data is written back to the memory the microprocessors have traditionally the same width for the instructions and data. the 32-bit architecture would be more ef?cient in performance and could also address a much larger address space compared to 16-bit architectures. the code density for 16-bit architecture would be much higher than 32-bit and the performance would be greater than half the 32-bit performance. the arm thumb instructions concept addresses the issues when 16-bit instructions are used but the performance required is 32-bit architecture. therefore the aim of the thumb instruction set can be summarized as follows: ? higher performance for 16-bit architecture, if 16-bit instructions are to be used. ? the code density achieved with 16-bit instructions in a 32-bit architecture is the most ef?cient use of memory space. 7.2 static memory interface unit (smiu) the ahb sram controller implements an ahb slave interface to an external sram. this interface is only available in the development version of this device. the speci?cation of this interface is described below: ? 32-bit ahb interface width ? 76 mhz maximum ahb operating frequency ? con?gured for low latency ? maximum of two srams/roms/flash/burst rom of 2 mb each, can be accessible ? 32-bit data table 15. performance characteristics for arm7tdmi-s process technology performance (mips/mhz) power consumption (mw/mhz) maximum operating frequency (mhz) typical operating frequency requirements for saf784x (mhz) 0.18 m m 0.9 0.39 76 76 [1]
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 68 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder ? amba ahb-compliant ? asynchronous burst mode read access from burst mode rom and flash devices ? asynchronous page mode read access in non-clocked memories ? 8-bit and 16-bit wide data paths ? independent con?guration of two memory banks, with maximum access of 2 mb each ? programmable wait-state up to a maximum of 31. this parameter in?uences the response times from external memory, typically access times ? programmable output-enable and write control-enable delays (15 cycles maximum) ? byte lane select outputs for eight bits or 16 bits; this can be a useful feature if access is only required for either lower or upper bytes of data width ? little endian con?guration: this has been ?xed ? programmable chip-select polarity 7.2.1 smiu operation modes the static memory interface unit can connect to two external memories. each of these two memories can be accessed sequentially. the static memory interface unit consist of memory banks that map the external memories to the main system memory address space. the versatility of the static memory interface unit enables access to a wide range of memory types with different memory access times. the static memory interface unit only supports asynchronous memory types that do not require the use of a system clock. each of the two memory banks is capable of supporting the following memory types: ? sram/psram ? rom ? flash eprom ? burst rom memory each of the above memories can be con?gured to either 8-bit or 16-bit external memory data paths. the static memory interface unit has been con?gured to support only little endian operation. 7.2.2 selecting the memory banks the access to the memory begins by asserting the chip-select lines to each of the two memory banks supported. the polarity of the chip-select lines can be programmed to be either active high or active low (default). a memory bank is selected by the arm addressing the static memory interface unit. this is achieved on the saf784x as follows: ? arm ahb address[27:26] = 0, 0 selects bank 0 ? arm ahb address[27:26] = 0, 1 selects bank 1
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 69 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 7.2.3 read access to external memories the sections below describe the step-by-step process required for setting up the static memory interface unit registers prior to accessing the external memory. 7.2.3.1 programming the external memory data widths the bank con?guration register smbcrx (x = bank number, 0 or 1), is used to describe the bus width. the saf784x can only support an external data bus width of 16-bits. if, during a data transfer requested by the internal arm, the external data width is narrower than the arm bus data width, several interface bus cycles may be required to complete the transfer. for example, if the external memory data bus is 16-bits wide, and a 32-bit read is requested by the arm, the ahb bus is stalled until the static memory interface unit has fetched the two half words. 7.2.3.2 wait-state generation the wait-state assertion registers are smbwst1rx and smbwst2rx. note that x denotes the bank number (0 or 1). the wait-state time is crucial, as the internal ahb bus cycles are scaled with respect to the access times of the external memory. the highest number of wait-states that can be asserted is 31 system clock cycles. the maximum ahb clock frequency for the saf784x, is 76 mhz. hence the maximum access time that can be supported for this implementation of wait-state register is 13 ns 31 cycles. the minimum wait-state assertion time is when the wait-state ?eld in the register is 0 and the hardware asserts a wait time of 2 13 ns. this is the fastest external memory access time. this is an important parameter to consider when selecting the memory type to interface with the static memory interface unit. each wait-state register has a particular importance for the following actions: smbwst1rx when performing read transfers from external memory; smbwst2rx when performing write transfers to external registers. an example of the effect of wait-state assertion when reading from external memory is shown in figure 38 . 7.2.3.3 output-enable delay programming the output enable can be programmed, at the time it needs to be active. this is typically after the memory has been selected, by toggling the chip-select lines. the maximum programmable delay between when the chip-select is active and when the output-enable activates is 15 cycles. the output-enable delay value is programmed in ?eld wstoen in register smbcrx. this feature is intended for memory that may not be able to provide valid output immediately after the chip-select lines are active. note that the output-enable is de-asserted at the same time as the chip-select lines at the end of a transfer. remark: the output-enable delay programmed in wstoen must be less than the programmed wait-state. note that the external memory access times are determined by the wait-states and not by the output-enable delay.
xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxx x x x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xx xx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxx x x xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx xxx saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 70 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder fig 38. default wait-state assertion during read from external memory 001aag349 address to external memory 13 ns cycle time (assuming max frequency for cmusic) address from arm processor read/write control address at the memory data read from the memory data read by the arm processor output enable /chip select to the memory access time of memory normal 2 cycle delay, before data is read by the arm processor (when 0 wait states programmed in smbwst1rx register; 1 wait state = 1 internal cycle) data available from the output of memory data from memory read by arm processor address seen on input of external memory
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 71 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 7.2.3.4 burst reads from external memory the static memory control unit can support a maximum of four consecutive reads from external reads. this feature supports burst mode rom devices. this feature increases the bandwidth for sequential reads compared to non-sequential reads. the burst access requires the user to specify the access times in smbwst2x; for single reads, the access times are speci?ed as wait-states in smbwst1x. the chip-select and output-enable lines are held during burst mode transfers. it is also important to note that the burst transfers cannot cross quad boundaries. for eight bits, this implies: arm address[1:0] = 11, and for 16 bits: arm address[2:1] = 11. example for a 16-bit wide external memory: 1. if start address is arm address[2:1] = 01, this address starts as a slow read, and hence the smbwst1x value applies. 2. the next sequential address is arm address[2:1] = 10 and 11. these addresses are fast reads and hence the smbwst2x value applies. 3. the ?nal address before the burst transfer completes is arm address[2:1] = 00. the ?nal read is slow (more wait-states apply), and the smbwst1x value applies. 7.2.4 write access to external memory writing to external memory requires a similar setup to that described for reading from external memory. the write-enable parameter needs to be programmed. writing to external memory can be extended by applying wait-states as described for reading from external memory. 7.2.4.1 write-enable programmable delay this is the programmable delay between the asserted chip-select and the asserted write-enable. a total of 15 cycles can be asserted. the wait-state values are programmed in ?eld wsten in register smbcrx. when no write-enable delay is programmed, the hardware introduces a default delay of one clock cycle between active chip-select and asserting write control. the write-enable delay programmed in wsten must be less than the wait-state programmed in register smbwst2x. 7.2.5 smiu operation parameters to calculate latency the delay through the logic to external memory are categorized in three sections: ? default hardware latency, with no software-programmable increase in delay ? software-programmable increase in latency delay ? standard delay through logic including pads the following requirements must be taken into account when computing the overall latency delay:
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 72 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder ? maximum arm operating frequency for the saf784x: for applications supporting wma decoding, the arm operating frequency is ?xed at 76 mhz ? external memory access times: critical for determining the allowable delay that is to be programmed via software, or the delay through the hardware the equation for read latency delay for sequential reads. this is the worst case latency, with no burst reads: ? memory address delay to external memory = one internal clock cycle. ? external memory data to internal arm = two internal cycle delay (?xed). ? additional delay, to increased set-up times; maximum delay is given as follows: C two internal cycles (?xed by hardware) + 31 cycle time (arm processor frequency). C 31 cycles: the value that can be programmed in either register smbwst1x or smbwst2x. 7.3 program rom interface the rom interface provides an interface between the on-board 130 kb rom memory and the arm via the ahb bus. the interface speci?cation is described below: ? 32-bit ahb interface width ? 76 mhz maximum ahb operating frequency ? con?gured for low latency ? 32-bit data ? amba ahb-compliant the low-latency architecture is optimized for low-speed operation. no wait-states are used and the rom control signals are taken directly from the ahb bus. this means that the maximum frequency is likely to be limited by the speed at which the control signals arrive from the ahb master. 7.4 boot rom interface the rom interface provides an interface between the on-board 42 kb rom memory and the arm via the ahb bus. the interface speci?cation is described below: ? 32-bit ahb interface width ? 76 mhz maximum ahb operating frequency ? con?gured for low latency ? 32-bit data ? amba ahb-compliant the low-latency architecture is optimized for low-speed operation. no wait-states are used and the rom control signals are taken directly from the ahb bus. this means that the maximum frequency is likely to be limited by the speed at which the control signals arrive from the ahb master.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 73 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 7.5 embedded kflash interface the kflash controller is an interface between the embedded flash memory device and ahb bus. the ahb embedded flash controller connects embedded flash memory devices to the ahb bus. the embedded flash controller supports full ahb bus protocol and will never generate a retry or split response. the data path between the memory and the controller is ?xed at 128-bit width to implement a double 128-bit cache line for creating a read performance comparable to reading sram, for cache hits. the controller features a programmable number of wait cycles. a user can select between 0 and 255 wait cycles, to allow for an optimal performance with the chosen flash instance at the clock frequency of the speci?c application. the design is optimized to interface with an arm cpu with embedded jtag tap controller: ? 32-bit amba ahb protocol with 76 mhz ahb operating frequency ? ahb reads for sub-word and word size ? ahb register interface ? zero wait-states, sustained read throughput on linear reads ? programmable wait-state counter for read with cache miss, including zero wait-state for low frequencies ? cache for 2 128-bit words ? jtag interface access to flash memory 7.6 ram interface the ram interface provides an interface between the on-board 110 kb sram memory and the arm via the ahb bus. the speci?cation of this interface is described below. ? 32-bit ahb interface width ? 76 mhz maximum ahb operating frequency ? con?gured for low latency ? ahb reads and writes for sub-words and word sizes ? 32-bit data 7.7 i 2 c-bus interface this interface can be used as an i 2 c-bus slave or master and is fully compliant with the i 2 c-bus speci?cation. the speci?cation of this interface is described as follows: ? master/slave con?gurations ? address 0x6e ? 76 mhz maximum ahb operating frequency
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 74 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder ? 8.4672 mhz i 2 c-bus operating frequency ? 4 b rx fifo depth ? 4 b tx fifo depth ? maximum i 2 c-bus frequency of 400 khz ? compatible with 7-bit and 10-bit addressing 7.8 general purpose i/os the gpios are linked to the vpb bus. this interface provides individual control over each bidirectional pin. each pin can be con?gured to be an input, output or bidirectional: ? 32 bidirectional i/os 7.9 interrupt controller ? 26 dedicated internal interrupts ? two external interrupts which have programmable polarity ? two interrupt types available: interrupt request (irq), and fast interrupt request (fiq) ? interrupts can be de?ned as irq or fiq ? one of 32 priority levels can be assigned to an interrupt ? interrupt priority threshold level ? all interrupts are maskable 7.10 uart interfaces ? compatibility with uart industry standard 16550 ? 16-deep transmit and receive fifo size ? receive fifo with error ?ags ? software-selectable baud rate generator including fractional pre-scaler ? four selectable receive fifo interrupt trigger levels ? standard asynchronous error and framing bits (start, stop, and parity overrun, break) ? maximum uart clock frequency of 50 mhz ? transmit, receive, line status, and data set interrupts independently controlled ? fully-programmable character formatting ? auto-baud functionality for detecting the incoming baud rate ? false start-bit detection (debounce) ? complete status reporting capability ? line break generation and detection ? loop-back controls for isolating communication link faults ? prioritized interrupt system controls ? optional arm dma controller ?ow-control interface ? amba vpb-compliant register interface
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 75 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 7.11 timers ? conforms to the vlsi peripheral bus (vpb) interface speci?cation ? clock prescaler for external high-frequency sources ? the vpb timer operates in two fully independent clock domains: C vpb_clk for accessing control and status registers (76 mhz maximum) C timer_clk for the timer/counter function (50 mhz maximum) ? the vpb timer can support up to four match registers having: C continuous operation with optional interrupt generation on match C stop on match, with or without, interrupt generation C reset on match, with or without, interrupt generation ? optional external match noti?cation pins with the following features: C set low on match C set high on match C toggle on match C no action on match ? up to four capture registers and capture trigger pins with optional interrupt generation on a capture event ? interrupt generation on match event and capture event 7.12 watchdog timer ? con?gurable watchdog feature including: C watchdog timer restart trigger protection by key C watchdog timer reload value protection by key access sequence C watchdog timer reset disable (for debug) protection by key ? interrupt generation watchdog time-out event 7.13 real-time clock ? zero wait-state to access all registers from the vpb interface ? provide coherent fraction and seconds time ? requirement for external 32 khz crystal ? alarm and tick interrupts will be generated even when the vpb clock is switched off ? vpb rtc interrupt ? real-time clock and vpb clock may be asynchronous (the vpb clock frequency could be higher or lower than the rtc clock frequency) ? maximum vpb slave frequency: 50 mhz 7.14 dma controller the single operation dma interface (sdma), is a small ahb bus master speci?cally designed for bulk memory transfers over the arm ahb bus.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 76 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder for memory-to-memory transfers, the length of the operation is speci?ed. when half of this length is reached, or when the end of the transfer has been reached, the cpu can be interrupted or the cpu can poll for noti?cation of this event. the sdma controller has a maximum of six channels, each channel can be con?gured with its own source, destination, length and control information. the sdma controller is primarily dedicated from sector transfers from segmentation manager to the arm sub-system ram. ? performs memory-to-memory copies in two ahb cycles, and memory-to-peripheral or peripheral-to-memory in three ahb cycles ? supports byte, half-word and word transfers, and correctly aligns it over the ahb bus ? compatible with arm ?ow control, for single requests (sreq), last single requests (lsreq), terminal count info (tc) and dma clearing (clr) ? saf784x architecture supports little endian for data transfers ? contains maskable interrupts for each raw irq 7.15 back-end audio processing the back-end audio processing entails the parallel-to-serial i 2 s conversion, sample-rate conversion for mp3 decoding and ebu data format generation. 7.15.1 parallel-to-serial i 2 s conversion ? can operate in both master and slave modes ? capable of handling nxp i 2 s format of 8-bit, 16-bit and 32-bit word sizes ? mono and stereo audio data supported ? the sampling frequency can range (in practice) from 16 khz to 48 khz (16 khz, 22.05 khz, 32 khz, 44.1 khz or 48 khz) ? two fifos are provided as data buffers, one for transmitting and one for reception; the depth of these fifos is con?gurable in hdli ? generates interrupt request ? generates two dma requests ? controls include reset, stop, and mute options ? dma acknowledge signals 7.15.2 variable sample-rate converter the hardware sample-rate conversion receives inputs from a varying input source. the input is an i 2 s stereo audio signal. the sample-rate conversion block converts the frequency into a ?xed 44.1 khz audio output signal. the block works at a ?xed frequency: 16.9344 mhz (384 44.1 khz, or 67.7376 mhz / 4). the audio input frequencies can range from 8 khz to 48 khz. the block converts the i 2 s input signal to a signal with a ?xed sampling frequency of 44.1 khz. the incoming i 2 s signal is stored in a buffer. the signal is upsampled by a variable upsampling factor n. after a variable hold, the signal is down-converted with a ?xed down-sample factor m.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 77 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 7.15.3 ebu interface the channel decoder contains a digital 1-wire ebu or s/pdif output interface. it formats data according to speci?cation iec 958. the ebu rate can be selected to be 1 cd-speed or 2 cd-speed. for proper operation of the ebu interface, the i 2 s bclk must be internally generated, bit clock gating must be disabled, and the following relationship between ebuclk, i 2 s bclk and i 2 s-format must be true: ebuclk = wclk 64 some ?elds in the user channel of the ebu stream can be ?lled by software. 7.16 reset functionality the device reset is crucial to the application as it allows the application to be initialized in the correct state before the key functions of the device can be exercised. the device reset function depends on the following requirements: ? power supply ? system clock ? reset assertion normal reset application can be summarized as follows: the device reset must be asserted asynchronously, that is, dependent only on the power supply and the reset pin reset, and de-asserted synchronously, that is, the system clock oscin needs to be available before starting the application. 7.16.1 power supply requirements the saf784x is dependent on two supply voltages of 3.3 v and 1.8 v. it is recommended that the system solutions ensure the correct supply voltages are applied, during power-up and available during device initialization via a reset. 7.16.2 system clock the saf784x can support two types of external crystal frequencies of 8.4672 mhz and 16.9344 mhz. the digital logic is clocked at lower frequencies to ensure minimum power consumption during initialization. fig 39. vsrc block diagram 001aag350 buffer variable hold n m pll
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 78 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder the requirement for reset is the availability of the clocks during synchronous reset de-assertion. 7.16.3 assertion of reset the polarity of reset assertion is active low. during reset assertion the internal logic is initialized into the correct state. due to the nature of complex logic, the initialization time may not be instantaneous. the minimum time that needs to be adhered to for the device to initialize into its correct state is shown in figure 40 . during reset de-assertion, the main criterion is to ensure that the fully-synchronous internal logic is supplied with internal system clocks. 8. limiting values [1] all digital inputs and bidirectional pins are 5 v tolerant. fig 40. 5 v tolerant reset input 001aag351 2.0 v reset assertion active low reset for minimum of 10 ms 0.8 v reset de-assertion permanent state of reset the rise time is typically 6 ns table 16. limiting values in accordance with the absolute maximum rating system (iec 60134). symbol parameter conditions min max unit v ddd(c) core digital supply voltage - 0.5 +2.5 v v ddd digital supply voltage - 0.5 +3.6 v v dda analog supply voltage - 0.5 +3.6 v v i(a) analog input voltage - 0.5 v dda + 0.5 v v i(dig) digital input voltage [1] - 0.5 +5.5 v v esd electrostatic discharge voltage human body model 2000 - v machine model 200 - v t stg storage temperature - 55 +125 c
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 79 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 9. recommended operating conditions 10. characteristics table 17. operating conditions symbol parameter conditions min typ max unit v ddd(c) core digital supply voltage 1.65 1.80 1.95 v v ddd digital supply voltage 3.0 3.3 3.6 v v dda analog supply voltage 3.0 3.3 3.6 v t amb ambient temperature - 40 +25 +85 c table 18. characteristics v ddd = v dda = 3.0 v to 3.6 v; v ddd(c) = 1.65 v to 1.95 v; t amb = 25 c; unless otherwise stated. symbol parameter conditions min typ max unit supply (t amb = - 40 c to +85 c) v ddd(c) core digital supply voltage 1.65 1.8 1.95 v v ddd digital supply voltage 3.0 3.3 3.6 v v dda analog supply voltage 3.0 3.3 3.6 v i ddd(c) core digital supply current v ddd(c) = 1.8 v [1] 9.6 [2] 15.5 42.4 ma i ddd digital supply current v ddd = 3.3 v [1] 11.1 [2] 11.1 11.1 ma i dda analog supply current v dda = 3.3 v [3] 63.6 [2] 63.6 63.6 ma analog section (v dda = 3.3 v; v ssa1 = v ssa2 = v ssa3 = 0 v) lf path inputs: r1 and r2 v m peak voltage unipolar 20 - 960 mv bipolar 20 - 960 mv d g/g gain variation within one channel - 20 - +20 % between two channels - 3+0+3% v candc /v range dc cancellation voltage to range voltage ratio unipolar - 66 - bipolar - 33 - v candcacc /v range accuracy of dc cancellation voltage to range voltage ratio full scale - 4.1 - % f s sampling frequency - 4.2336 - mhz f i input frequency - 8.4672 - mhz b bandwidth recovered 20 - - khz s/n signal-to-noise ratio 0 khz to 20 khz 55 - - db thd total harmonic distortion 0 khz to 20 khz - - - 30 db r i input resistance b = 0 khz to 20 khz 20 - - k w d r i /r i relative input resistance variation - 30 - +30 % v i(cm) common-mode input voltage - 1.6 - v v offset offset voltage relative to opu_ref_out - 30 - +30 mv hf path inputs: d1, d2, d3 and d4
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 80 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder v i(dif)(p-p) peak-to-peak differential input voltage 6-bit adc 1.4 1.4 1.4 v v i(cm) common-mode input voltage 6-bit adc 2 - - v b bandwidth up to 6 (2 mhz x-rate) 12 - - mhz d t d( j ) phase delay time variation up to 6 (10 ns / x-rate) - - 1.66 ns s/n signal-to-noise ratio 100 hz to 12 mhz - - 28 db v i(adc)se(p-p) peak-to-peak single-ended adc input voltage at 6 mhz peak-to-peak - - 1 v thd total harmonic distortion at 6 mhz - - - 35 db psrr power supply rejection ratio 40 - - db g tot total gain 2.4 - 38.4 db z i input impedance nominal 20 20 20 k w b bandwidth - 3 db point 27 - 46 mhz audio dac input/output: dac_vref outputs: dac_ln, dac_lp, dac_rn and dac_rp s/n signal-to-noise ratio a-weighted - 90 - db thd total harmonic distortion at 1 khz - - - 80 db audio feature inputs: aux_l and aux_r s/n signal-to-noise ratio referenced to lf path values - 6065db thd total harmonic distortion referenced to lf path values - - 60 - 30 db laser driver input: monitor i o(monitor) output current on pin monitor 120 - - ma t startup(laser) laser start-up time 1 - - ms v n(monitor) noise voltage on pin monitor - 1 - +1 mv v monitor(dc) dc voltage on pin monitor sel180 = 0 145 - 155 mv sel180 = 1 175 - 185 mv iref reference output: opu_ref_out v ref(bg) band gap reference voltage 1.14 1.2 1.26 v i o output current 20 25 30 m a oscillator pin: oscin (external clock) v i input voltage - 0.5v dda -v t ih /t relative high input time 45 - 55 % i li input leakage current - 20 - +20 m a c i input capacitance - - 7 pf table 18. characteristics continued v ddd = v dda = 3.0 v to 3.6 v; v ddd(c) = 1.65 v to 1.95 v; t amb = 25 c; unless otherwise stated. symbol parameter conditions min typ max unit
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 81 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder pin: oscout f osc oscillator frequency crystal [4] 8.4672 - 16.9344 mhz resonator 8.4672 - 16.9344 mhz g m transconductance 17 - - ms c fbck feedback capacitance - - 2 pf c o output capacitance - - 7 pf r bias(int) internal bias resistance - 200 - k w real time clock oscillator pin: osc_32k_in (external clock) v il low-level input voltage - - 0.2v dda v v ih high-level input voltage 0.8v dda --v t ih /t relative high input time relative to period 45 - 55 % i li input leakage current - 1.5 2.5 m a c i input capacitance - - 7 pf pin: osc_32k_out f osc oscillator frequency crystal [4] - 32.768 - khz resonator - 32.768 - khz g m transconductance - 4 - ms c o output capacitance - 100 300 pf pinning characteristics (t amb = - 40 c to +85 c) general i il low-level input current v i = 0 v; no pull up - - 1 m a i ih high-level input current v i = v ddd --1 m a i ozl low off-state output current v o = 0 v or v o =v ddd --1 m a i latch i/o latch-up current - (0.5v ddd ) < v i < (1.5v ddd ); t j < 125 c 100 - - ma power i cont continuous current - - 98 ma digital pins (t amb = - 40 c to +85 c) dc speci?cations; input v ih high-level input voltage 2.0 - - v v il low-level input voltage - - 0.8 v v hys hysteresis voltage 0.4 - - v dc speci?cations; output v oh high-level output voltage v ddd - 0.4 --v v ol low-level output voltage - - 0.4 v table 18. characteristics continued v ddd = v dda = 3.0 v to 3.6 v; v ddd(c) = 1.65 v to 1.95 v; t amb = 25 c; unless otherwise stated. symbol parameter conditions min typ max unit
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 82 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder [1] pins vddd1, vddd2 and vddd3. [2] initial reset value with primary clock = 76 mhz, ahb and decoder = 4 mhz. [3] pins vdda1, vdda2 and vdda3. [4] it is recommended that the nominal running series resistance of the crystal or ceramic resonator is 60 w . i oh high-level output current 5 ns slew rate output; v oh = v ddd - 0.4 v - 5--ma 12 ma output; v oh = v ddd - 0.4 v - 13--ma 27 ma output; v oh =v ddd - 0.4 v - 28--ma i ol low-level output current 5 ns slew rate output; v ol = 0.4 v 4--ma 12 ma output; v ol = 0.4 v 11--ma 27 ma output; v ol = 0.4 v 27--ma i osh high-level short-circuit output current v oh = 0 v - - - 45 ma i osl low-level short-circuit output current v ol = v ddd - - 50 ma i pd pull-down current v i = v ddd 20 50 75 m a v i = 5 v 20 50 75 m a i pu pull-up current v i = 0 v - 13 - 50 - 40 m a v ddd < v i < 5.0 v 0 0 0 m a ac speci?cations; input t r rise time - 6 200 ns t f fall time - 6 200 ns ac speci?cations; output t thl high to low transition time load = 30 pf; transition time read at 10 % and 90 % of output slope 5 ns slew rate output - 4.0 - ns 12 ma output - 2.9 - ns 27 ma output - 3.8 - ns t tlh low to high transition time load = 30 pf; transition time read at 10 % and 90 % of output slope 5 ns slew rate output - 4.0 - ns 12 ma output - 2.9 - ns 27 ma output - 3.8 - ns table 18. characteristics continued v ddd = v dda = 3.0 v to 3.6 v; v ddd(c) = 1.65 v to 1.95 v; t amb = 25 c; unless otherwise stated. symbol parameter conditions min typ max unit
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 83 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 11. test information 11.1 quality information this product has been quali?ed in accordance with the automotive electronics council (aec) standard q100 - stress test quali?cation for integrated circuits , and is suitable for use in automotive applications.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 84 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 12. package outline fig 41. package outline sot486-1 (lqfp144) unit a 1 a 2 a 3 b p ce (1) eh e ll p z y w v q references outline version european projection issue date iec jedec jeita mm 0.15 0.05 1.45 1.35 0.25 0.27 0.17 0.20 0.09 20.1 19.9 0.5 22.15 21.85 1.4 1.1 7 0 o o 0.08 0.2 0.08 1 dimensions (mm are the original dimensions) note 1. plastic or metal protrusions of 0.25 mm maximum per side are not included. 0.75 0.45 sot486-1 136e23 ms-026 00-03-14 03-02-20 d (1) (1) (1) 20.1 19.9 h d 22.15 21.85 e z 1.4 1.1 d 0 5 10 mm scale b p e q e a 1 a l p detail x l (a ) 3 b c b p e h a 2 d h v m b d z d a z e e v m a x y w m w m a max. 1.6 lqfp144: plastic low profile quad flat package; 144 leads; body 20 x 20 x 1.4 mm sot486-1 108 109 pin 1 index 73 72 37 1 144 36
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 85 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 13. soldering of smd packages this text provides a very brief insight into a complex technology. a more in-depth account of soldering ics can be found in application note an10365 surface mount re?ow soldering description . 13.1 introduction to soldering soldering is one of the most common methods through which packages are attached to printed circuit boards (pcbs), to form electrical circuits. the soldered joint provides both the mechanical and the electrical connection. there is no single soldering method that is ideal for all ic packages. wave soldering is often preferred when through-hole and surface mount devices (smds) are mixed on one printed wiring board; however, it is not suitable for ?ne pitch smds. re?ow soldering is ideal for the small pitches and high densities that come with increased miniaturization. 13.2 wave and re?ow soldering wave soldering is a joining technology in which the joints are made by solder coming from a standing wave of liquid solder. the wave soldering process is suitable for the following: ? through-hole components ? leaded or leadless smds, which are glued to the surface of the printed circuit board not all smds can be wave soldered. packages with solder balls, and some leadless packages which have solder lands underneath the body, cannot be wave soldered. also, leaded smds with leads having a pitch smaller than ~0.6 mm cannot be wave soldered, due to an increased probability of bridging. the re?ow soldering process involves applying solder paste to a board, followed by component placement and exposure to a temperature pro?le. leaded packages, packages with solder balls, and leadless packages are all re?ow solderable. key characteristics in both wave and re?ow soldering are: ? board speci?cations, including the board ?nish, solder masks and vias ? package footprints, including solder thieves and orientation ? the moisture sensitivity level of the packages ? package placement ? inspection and repair ? lead-free soldering versus snpb soldering 13.3 wave soldering key characteristics in wave soldering are: ? process issues, such as application of adhesive and ?ux, clinching of leads, board transport, the solder wave parameters, and the time during which components are exposed to the wave ? solder bath speci?cations, including temperature and impurities
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 86 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 13.4 re?ow soldering key characteristics in re?ow soldering are: ? lead-free versus snpb soldering; note that a lead-free re?ow process usually leads to higher minimum peak temperatures (see figure 42 ) than a snpb process, thus reducing the process window ? solder paste printing issues including smearing, release, and adjusting the process window for a mix of large and small components on one board ? re?ow temperature pro?le; this pro?le includes preheat, re?ow (in which the board is heated to the peak temperature) and cooling down. it is imperative that the peak temperature is high enough for the solder to make reliable solder joints (a solder paste characteristic). in addition, the peak temperature must be low enough that the packages and/or boards are not damaged. the peak temperature of the package depends on package thickness and volume and is classi?ed in accordance with t ab le 19 and 20 moisture sensitivity precautions, as indicated on the packing, must be respected at all times. studies have shown that small packages reach higher temperatures during re?ow soldering, see figure 42 . table 19. snpb eutectic process (from j-std-020c) package thickness (mm) package re?ow temperature ( c) volume (mm 3 ) < 350 3 350 < 2.5 235 220 3 2.5 220 220 table 20. lead-free process (from j-std-020c) package thickness (mm) package re?ow temperature ( c) volume (mm 3 ) < 350 350 to 2000 > 2000 < 1.6 260 260 260 1.6 to 2.5 260 250 245 > 2.5 250 245 245
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 87 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder for further information on temperature pro?les, refer to application note an10365 surface mount re?ow soldering description . 14. abbreviations msl: moisture sensitivity level fig 42. temperature pro?les for large and small components 001aac844 temperature time minimum peak temperature = minimum soldering temperature maximum peak temperature = msl limit, damage level peak temperature table 21. abbreviations acronym description acu address calculation unit adc analog-to-digital converter agc automatic gain control ahb arm advanced high performance bus alu arithmetic logic unit amba advanced microcontroller bus architecture aoc automatic offset compensation arm advanced risc machines (32-bit microprocessor design) bler block error rate cn check bit n ca central aperture cav constant angular velocity cd compact disc cd-da compact disc digital audio cd-mp3 compact disc moving picture experts group cd-r compact disc recordable cd-rom compact disc read-only memory cd-rw compact disc recordable/writable cd-wma compact disc windows media audio
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 88 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder circ cross interleave reed-solomon code clv constant linear velocity cpu central processing unit crc cyclic redundancy check dac digital to analog converter dem dac dynamic element matching dac dc direct current dma direct memory access efm eight to fourteen modulation (efm+ has added bits for cd coding with no digital content) erco error corrector fifo first in first out gpai general purpose analog input gpio general purpose input output hdli high-level description language integrator hf high frequency hpf high pass filter hsi hardware software interface ice in-circuit emulator iir in?nite impulse response irq interrupt request lf low frequency lpf low pass filter lsb least signi?cant bit mimed2 minimum memory decoder interface decoder second generation mp3 moving picture experts group msb most signi?cant bit msf minutes seconds frames nf noise filter opu optical pick up pdm pulse density modulation pdsic parallel digital servo integrated circuit pi proportional-integral pid proportional-integral and differential pll phase-locked loop psram pseudo-static random access memory pwm pulse-width modulator ram random access memory re radial error risc reduced instruction set computer rl run length table 21. abbreviations continued acronym description
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 89 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 15. glossary arm7tdmi-s speci?c version of arm microprocessor used in the saf784x (arm7 family) dark currents currents caused by unwanted light leakage into the opu causing offsets, otherwise known as dark current offsets flexi servo hardware which gives the arm microprocessor access to the servo input signals and to drive the servo outputs. allows servo algorithms to be performed in software in the arm core. i 2 c inter ic communication format i 2 s inter ic sound format pdsic parallel digital servo ic (digital servo block within saf784x) thumb arm 16-bit instruction set rom read only memory rtc real time clock sacd super audio compact disc smiu static memory interface unit s/pdif sony/philips digital interface format sram static random access memory src sample rate converter tpi track position indicator uart universal asynchronous receiver transmitter vlsi very large scale integration vpb vlsi peripheral bus vsrc variable sample rate converter wdt watchdog timer wma windows media audio table 21. abbreviations continued acronym description
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 90 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 16. revision history table 22. revision history document id release date data sheet status change notice supersedes saf784x_2 20080509 product data sheet - saf784x_1 modi?cations: ? t ab le 18 char acter istics : clari?ed presentation of ambient temperature information ? replaced instances of with text or values in section 6.5.10.7 , t ab le 16 and t ab le 18 . saf784x_1 20071214 preliminary data sheet - -
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 91 of 93 nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 17. legal information 17.1 data sheet status [1] please consult the most recently issued document before initiating or completing a design. [2] the term short data sheet is explained in section de?nitions. [3] the product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple dev ices. the latest product status information is available on the internet at url http://www .nxp .com . 17.2 de?nitions draft the document is a draft version only. the content is still under internal review and subject to formal approval, which may result in modi?cations or additions. nxp semiconductors does not give any representations or warranties as to the accuracy or completeness of information included herein and shall have no liability for the consequences of use of such information. short data sheet a short data sheet is an extract from a full data sheet with the same product type number(s) and title. a short data sheet is intended for quick reference only and should not be relied upon to contain detailed and full information. for detailed and full information see the relevant full data sheet, which is available on request via the local nxp semiconductors sales of?ce. in case of any inconsistency or con?ict with the short data sheet, the full data sheet shall prevail. 17.3 disclaimers general information in this document is believed to be accurate and reliable. however, nxp semiconductors does not give any representations or warranties, expressed or implied, as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such information. right to make changes nxp semiconductors reserves the right to make changes to information published in this document, including without limitation speci?cations and product descriptions, at any time and without notice. this document supersedes and replaces all information supplied prior to the publication hereof. suitability for use nxp semiconductors products are not designed, authorized or warranted to be suitable for use in medical, military, aircraft, space or life support equipment, nor in applications where failure or malfunction of an nxp semiconductors product can reasonably be expected to result in personal injury, death or severe property or environmental damage. nxp semiconductors accepts no liability for inclusion and/or use of nxp semiconductors products in such equipment or applications and therefore such inclusion and/or use is at the customers own risk. applications applications that are described herein for any of these products are for illustrative purposes only. nxp semiconductors makes no representation or warranty that such applications will be suitable for the speci?ed use without further testing or modi?cation. limiting values stress above one or more limiting values (as de?ned in the absolute maximum ratings system of iec 60134) may cause permanent damage to the device. limiting values are stress ratings only and operation of the device at these or any other conditions above those given in the characteristics sections of this document is not implied. exposure to limiting values for extended periods may affect device reliability. terms and conditions of sale nxp semiconductors products are sold subject to the general terms and conditions of commercial sale, as published at http://www .nxp .com/pro? le/ter ms , including those pertaining to warranty, intellectual property rights infringement and limitation of liability, unless explicitly otherwise agreed to in writing by nxp semiconductors. in case of any inconsistency or con?ict between information in this document and such terms and conditions, the latter will prevail. no offer to sell or license nothing in this document may be interpreted or construed as an offer to sell products that is open for acceptance or the grant, conveyance or implication of any license under any copyrights, patents or other industrial or intellectual property rights. 17.4 trademarks notice: all referenced brands, product names, service names and trademarks are the property of their respective owners. i 2 c-bus logo is a trademark of nxp b.v. 18. contact information for more information, please visit: http://www .nxp.com for sales of?ce addresses, please send an email to: salesad dresses@nxp.com document status [1] [2] product status [3] de?nition objective [short] data sheet development this document contains data from the objective speci?cation for product development. preliminary [short] data sheet quali?cation this document contains data from the preliminary speci?cation. product [short] data sheet production this document contains the product speci?cation.
saf784x_2 ? nxp b.v. 2008. all rights reserved. product data sheet rev. 02 9 may 2008 92 of 93 continued >> nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder 19. contents 1 general description . . . . . . . . . . . . . . . . . . . . . . 1 2 features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2.1 features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2.2 formats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3 ordering information . . . . . . . . . . . . . . . . . . . . . 3 4 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 4 5 pinning information . . . . . . . . . . . . . . . . . . . . . . 5 5.1 pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 5.2 pin description . . . . . . . . . . . . . . . . . . . . . . . . . 5 6 functional description . . . . . . . . . . . . . . . . . . . 9 6.1 analog data acquisition. . . . . . . . . . . . . . . . . . . 9 6.1.1 lf acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6.1.2 hf acquisition . . . . . . . . . . . . . . . . . . . . . . . . . 11 6.2 analog clock generation . . . . . . . . . . . . . . . . . 12 6.3 general purpose analog inputs . . . . . . . . . . . 13 6.4 auxiliary analog inputs . . . . . . . . . . . . . . . . . . 13 6.5 channel decoder . . . . . . . . . . . . . . . . . . . . . . 16 6.5.1 features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 6.5.2 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . 16 6.5.3 clock control . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6.5.4 decoder-arm microprocessor interface. . . . . 20 6.5.4.1 programming interface . . . . . . . . . . . . . . . . . . 20 6.5.4.2 interrupt strategy. . . . . . . . . . . . . . . . . . . . . . . 21 6.5.5 efm bit detection and demodulation . . . . . . . 21 6.5.5.1 signal conditioning . . . . . . . . . . . . . . . . . . . . . 22 6.5.5.2 bit detector . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 6.5.5.3 limiting the pll frequency range . . . . . . . . . . 31 6.5.5.4 run length 2 push-back detector . . . . . . . . . . 31 6.5.5.5 available signals for monitoring . . . . . . . . . . . 32 6.5.5.6 use of jitter measurement. . . . . . . . . . . . . . . . 32 6.5.5.7 internal lock ?ags . . . . . . . . . . . . . . . . . . . . . . 33 6.5.5.8 format of the measurements signal meas1 on pin cl1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 6.5.5.9 demodulator . . . . . . . . . . . . . . . . . . . . . . . . . . 34 6.5.5.10 efm demodulation . . . . . . . . . . . . . . . . . . . . . 34 6.5.5.11 sync detection and synchronization . . . . . . . . 34 6.5.5.12 sync protection . . . . . . . . . . . . . . . . . . . . . . . . 34 6.5.6 cd decoding . . . . . . . . . . . . . . . . . . . . . . . . . . 35 6.5.6.1 general description of cd decoding. . . . . . . . 35 6.5.6.2 q-channel subcode interface . . . . . . . . . . . . . 35 6.5.6.3 cd-text interface . . . . . . . . . . . . . . . . . . . . . . . 36 6.5.7 main data decoding . . . . . . . . . . . . . . . . . . . . 37 6.5.7.1 data processing . . . . . . . . . . . . . . . . . . . . . . . 37 6.5.7.2 data latency + fifo operation . . . . . . . . . . . 37 6.5.7.3 safe and unsafe correction modes . . . . . . . . . 38 6.5.8 error corrector statistics . . . . . . . . . . . . . . . . . 38 6.5.8.1 cflg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 6.5.8.2 bler counters . . . . . . . . . . . . . . . . . . . . . . . . 39 6.5.9 audio back end and data output interfaces . . 39 6.5.9.1 audio processing . . . . . . . . . . . . . . . . . . . . . . 40 6.5.9.2 interpolate-and-hold . . . . . . . . . . . . . . . . . . . . 40 6.5.9.3 soft mute and error detection. . . . . . . . . . . . . 41 6.5.9.4 hard mute on ebu . . . . . . . . . . . . . . . . . . . . . 41 6.5.9.5 silence detection and kill generation . . . . . . . 41 6.5.9.6 de-emphasis ?lter . . . . . . . . . . . . . . . . . . . . . 41 6.5.9.7 upsample ?lter (four times) . . . . . . . . . . . . . . 42 6.5.9.8 data output interfaces . . . . . . . . . . . . . . . . . . 43 6.5.9.9 i 2 s interface . . . . . . . . . . . . . . . . . . . . . . . . . . 43 6.5.9.10 subcode (v4) interface. . . . . . . . . . . . . . . . . . 44 6.5.10 motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 6.5.10.1 frequency setpoint. . . . . . . . . . . . . . . . . . . . . 46 6.5.10.2 position error . . . . . . . . . . . . . . . . . . . . . . . . . 46 6.5.10.3 motor control loop gains (k p , k f and k i ). . . . . 46 6.5.10.4 operation modes . . . . . . . . . . . . . . . . . . . . . . 47 6.5.10.5 writing, reading motor integrator value . . . . . 47 6.5.10.6 some notes on application motor servo. . . . . 47 6.5.10.7 tacho . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 6.6 parallel digital servo ic (pdsic) . . . . . . . . . . 49 6.6.1 pdsic registers and servo ram control . . . . 49 6.6.2 diode signal processing . . . . . . . . . . . . . . . . . 51 6.6.3 signal conditioning . . . . . . . . . . . . . . . . . . . . . 52 6.6.4 focus servo system . . . . . . . . . . . . . . . . . . . . 53 6.6.4.1 focus start-up . . . . . . . . . . . . . . . . . . . . . . . . 53 6.6.4.2 focus position control loop. . . . . . . . . . . . . . . 53 6.6.4.3 dropout detection. . . . . . . . . . . . . . . . . . . . . . 55 6.6.4.4 focus loss detection and fast restart . . . . . . . 55 6.6.4.5 focus loop gain switching . . . . . . . . . . . . . . . 55 6.6.4.6 focus automatic gain control loop . . . . . . . . . 55 6.6.5 radial servo system. . . . . . . . . . . . . . . . . . . . 55 6.6.5.1 radial pid - on-track mode . . . . . . . . . . . . . . 55 6.6.5.2 level initialization . . . . . . . . . . . . . . . . . . . . . . 56 6.6.5.3 dropout detection. . . . . . . . . . . . . . . . . . . . . . 56 6.6.5.4 focus loss detection and fast restart . . . . . . . 57 6.6.5.5 focus loop gain switching . . . . . . . . . . . . . . . 57 6.6.5.6 focus automatic gain control loop . . . . . . . . . 57 6.6.6 radial servo system. . . . . . . . . . . . . . . . . . . . 57 6.6.6.1 level initialization . . . . . . . . . . . . . . . . . . . . . . 57 6.6.6.2 sledge control . . . . . . . . . . . . . . . . . . . . . . . . 57 6.6.6.3 tracking control . . . . . . . . . . . . . . . . . . . . . . . 57 6.6.6.4 access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 6.6.6.5 radial automatic gain control loop . . . . . . . . . 58 6.6.7 off-track counting . . . . . . . . . . . . . . . . . . . . . . 58 6.6.8 defect detection . . . . . . . . . . . . . . . . . . . . . . . 59 6.6.9 off-track detection . . . . . . . . . . . . . . . . . . . . . 59 6.6.10 high level features . . . . . . . . . . . . . . . . . . . . . 59
nxp semiconductors saf784x one chip cd audio device with integrated mp3/wma decoder ? nxp b.v. 2008. all rights reserved. for more information, please visit: http://www.nxp.com for sales office addresses, please send an email to: salesaddresses@nxp.com date of release: 9 may 2008 document identifier: saf784x_2 please be aware that important notices concerning this document and the product(s) described herein, have been included in section legal information. 6.6.10.1 automatic error handling. . . . . . . . . . . . . . . . . 59 6.6.10.2 automatic sequencers and timer interrupts . . 60 6.6.11 driver interface . . . . . . . . . . . . . . . . . . . . . . . . 60 6.7 flexi servo options . . . . . . . . . . . . . . . . . . . . . 60 6.7.1 modes of operation . . . . . . . . . . . . . . . . . . . . . 61 6.7.1.1 hardware servo-only. . . . . . . . . . . . . . . . . . . . 61 6.7.1.2 hardware servo with ?ne offset compensation . . . . . . . . . . . . . . . . . . . . . . . . . 61 6.7.1.3 fully ?exible servo . . . . . . . . . . . . . . . . . . . . . 61 6.7.1.4 pre-processing with hardware servo . . . . . . . 61 6.7.1.5 hardware servo with post-processing. . . . . . . 61 6.7.1.6 pre-processing with hardware servo plus post-processing . . . . . . . . . . . . . . . . . . . . . . . 61 6.8 block decoder . . . . . . . . . . . . . . . . . . . . . . . . . 62 6.8.1 supported modes of operation . . . . . . . . . . . . 63 6.8.2 channel decoder to block decoder interface (c2i) . . . . . . . . . . . . . . . . . . . . . . . . . 63 6.8.3 block decoder to segmentation manager interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 6.9 segmentation manager . . . . . . . . . . . . . . . . . 64 6.9.1 general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 6.9.2 interrupt generation . . . . . . . . . . . . . . . . . . . . 64 6.9.3 segmentation buffer arm sub-system interface. . . . . . . . . . . . . . . . . . . . 65 6.10 laser interface . . . . . . . . . . . . . . . . . . . . . . . . 66 7 arm7 system . . . . . . . . . . . . . . . . . . . . . . . . . . 66 7.1 arm7tdmi-s microprocessor . . . . . . . . . . . . 66 7.2 static memory interface unit (smiu) . . . . . . . 67 7.2.1 smiu operation modes . . . . . . . . . . . . . . . . . . 68 7.2.2 selecting the memory banks . . . . . . . . . . . . . 68 7.2.3 read access to external memories . . . . . . . . 69 7.2.3.1 programming the external memory data widths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 7.2.3.2 wait-state generation . . . . . . . . . . . . . . . . . . . 69 7.2.3.3 output-enable delay programming . . . . . . . . . 69 7.2.3.4 burst reads from external memory . . . . . . . . . 71 7.2.4 write access to external memory . . . . . . . . . . 71 7.2.4.1 write-enable programmable delay . . . . . . . . . 71 7.2.5 smiu operation parameters to calculate latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 7.3 program rom interface . . . . . . . . . . . . . . . . . 72 7.4 boot rom interface . . . . . . . . . . . . . . . . . . . . 72 7.5 embedded kflash interface . . . . . . . . . . . . . . 73 7.6 ram interface . . . . . . . . . . . . . . . . . . . . . . . . . 73 7.7 i 2 c-bus interface . . . . . . . . . . . . . . . . . . . . . . . 73 7.8 general purpose i/os . . . . . . . . . . . . . . . . . . . 74 7.9 interrupt controller . . . . . . . . . . . . . . . . . . . . . 74 7.10 uart interfaces . . . . . . . . . . . . . . . . . . . . . . . 74 7.11 timers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 7.12 watchdog timer. . . . . . . . . . . . . . . . . . . . . . . . 75 7.13 real-time clock. . . . . . . . . . . . . . . . . . . . . . . . 75 7.14 dma controller . . . . . . . . . . . . . . . . . . . . . . . . 75 7.15 back-end audio processing . . . . . . . . . . . . . . 76 7.15.1 parallel-to-serial i 2 s conversion . . . . . . . . . . . 76 7.15.2 variable sample-rate converter . . . . . . . . . . . 76 7.15.3 ebu interface . . . . . . . . . . . . . . . . . . . . . . . . . 77 7.16 reset functionality . . . . . . . . . . . . . . . . . . . . . 77 7.16.1 power supply requirements . . . . . . . . . . . . . . 77 7.16.2 system clock . . . . . . . . . . . . . . . . . . . . . . . . . 77 7.16.3 assertion of reset . . . . . . . . . . . . . . . . . . . . . . 78 8 limiting values . . . . . . . . . . . . . . . . . . . . . . . . 78 9 recommended operating conditions . . . . . . 79 10 characteristics . . . . . . . . . . . . . . . . . . . . . . . . 79 11 test information. . . . . . . . . . . . . . . . . . . . . . . . 83 11.1 quality information . . . . . . . . . . . . . . . . . . . . . 83 12 package outline . . . . . . . . . . . . . . . . . . . . . . . . 84 13 soldering of smd packages . . . . . . . . . . . . . . 85 13.1 introduction to soldering. . . . . . . . . . . . . . . . . 85 13.2 wave and re?ow soldering . . . . . . . . . . . . . . . 85 13.3 wave soldering. . . . . . . . . . . . . . . . . . . . . . . . 85 13.4 re?ow soldering. . . . . . . . . . . . . . . . . . . . . . . 86 14 abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . 87 15 glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 16 revision history . . . . . . . . . . . . . . . . . . . . . . . 90 17 legal information . . . . . . . . . . . . . . . . . . . . . . 91 17.1 data sheet status . . . . . . . . . . . . . . . . . . . . . . 91 17.2 de?nitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 17.3 disclaimers. . . . . . . . . . . . . . . . . . . . . . . . . . . 91 17.4 trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . 91 18 contact information . . . . . . . . . . . . . . . . . . . . 91 19 contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

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