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 SwitchStarTM ATM Cell Based 8 x 8 1.2Gbps non-blocking Integrated Switching Memory
Features List
Single chip supports an 8 x 8 port switch at 155Mbps per port ! Central Memory Architecture eliminates Head-of-Line Blocking by sharing the memory array with all ports ! Low power dissipation - 330mW (typ.) ! Data Path Interface (DPI) provides configurable Input and Output ports; up to 8 receive and 8 transmit ports at 155Mbps ! Supports data rates up to 1.2Gbps with a 32-bit wide port configuration; 155Mbps per 4-bit port ! Can be cascaded for larger switch configurations ! Fast Input/Output port cycle times ! Expander and Concentrator function is fully supported by the Input and Output port configuration options ! 8192 cells (52 to 56 bytes each) of on-chip buffer memory capacity
! !
IDT77V400
!
!
!
!
!
! ! !
Configurable cell lengths of 52, 53, 54, 55, or 56 bytes can be independently chosen for Input and Output ports Byte Addition or Byte Subtraction for x4/x8 to x16/x32 conversion capability Internal header Cyclical Redundancy Check (CRC) and generation logic on-chip Header modification, pre-pend, and post-pend operations available as well as Multicasting and Broadcasting capability High-bandwidth control port for queue controller system block, up to 36 MHz cycle time Can be used with the companion IDT77V500 Switch Controller or custom logic for traffic management Industrial temperature range (-40C to +85C) is available Single +3.3V 300mV power supply Available in an 208-pin Plastic Quad Flat Pack (PQFP) and 256-ball BGA
Block Diagram
External Interface for Global Setup and Control
8-bit Processor/ Call Setup Manager or IDT77V550
Data
Control
IDT77V500 Switch Controller
Data
Control
155Mbps PHY
Port 0
Port 0
155Mbps PHY
,
IDT77V400
Switching Memory
155Mbps PHY
Port 7 Port 7
155Mbps PHY
3606 drw 01
Figure 1 Typical 8x8 Switch Configuration using the IDT77V400 Switching Memory
SwitchStar and the IDT logo are registered trademarks of Integrated Device Technology, Inc.
1 of 26
2001 Integrated Device Technology, Inc.
March 31, 2001
DSC 3606/6
IDT77V400
Description
The IDT77V400 ATM Cell Based Switching Memory provides the logic and memory necessary to perform high-speed buffering and switching operations on ATM cell data. A single IDT77V400 provides a cost effective switching element to implement an 8 x 8 155Mbps switch with 1.2Gbps total switching bandwidth. The user configurable data ports provide an aggregate bandwidth of 1.2Gbps for both receive and transmit functions, and the cell lengths are user programmable to up to 56 bytes. The memory provides storage for 8192 ATM cells, each of which can be as large as 56-bytes in length. The main cell memory is implemented as a Buffer Memory array, and an on-chip cell address counter keeps track of cell refresh requirements. There are also sixteen double-buffered Serial Access Memories (SAM); eight for receiving and eight for transmitting the ATM cells. The input data ports and output data ports are configurable from eight ports of 4-bits at 155Mbps each up to one 32-bit wide port at 1.2Gbps. The sixteen data ports are asynchronous with respect to each other, and each port provides an independent data clock and cell framing signal for start of cell indication. The SAMs are double-buffered for each input and each output port to allow one cell to be transferred to or from the internal memory while that data port continues to receive or transmit a second cell. The cell framing and data clock signals implement a simple handshaking and synchronization protocol which allows multiple Switching Memories to be connected to construct larger switch arrays without requiring additional hardware. The control interface of the IDT77V400 includes a 6-bit Command Bus (CMD0-5), a 32-bit Control Data Bus (IOD0-31), a Chip Select pin (CS), a 4-bit Address field (ADDR0-3), a RESET pin, an Output Enable pin (OE), a Control Enable pin (CTLEN) and a CRCERR pin. All control operations are synchronized with respect to the System Clock (SCLK), with the exception of RESET, CTLEN, and OE, which are fully asynchronous. The internal configuration register of the IDT77V400 can be accessed through the Control Data Bus to define the cell length and the input and output data port configurations. Internal error and status registers contain status information regarding each SAM and are accessible via the Control Data Bus (IOD0-31). Input SAM full or Output SAM empty status for all SAMs may be obtained in one access operation. Additional information regarding the reception of short or long cells and Input SAM overflow may also be obtained through the Control Data Bus. The command set of the Switching Memory provides functions for storing cells in the shared memory, loading Output SAMs, polling the status of the data ports, retrieving and storing original or modified header bytes and pre-pend or post-pend bytes, and refreshing the cell memory. Header CRC errors are indicated by a LOW CRCERR pin; the CRC comparison byte may also be accessed via the status register, which indicates the IPort on which the error was detected. A new CRC can be generated upon storing a new header in the PHEC command. Cell headers may be modified upon cell reception at the input ports or
upon cell transmit at the output ports. User defined pre-pend and postpend bytes may also be stored, retrieved, and modified through the Control Data Bus. The IDT77V400 has a generic control interface which supports a variety of queuing disciplines. By maintaining the memory control in an external controller, system level switching performance may be modified over time as requirements change. In normal operation, the Switching Memory port status is polled by the control function through the Control Data Bus. Upon receiving a cell, the control function can retrieve the header, check the CRC result, and store a new header if needed prior to moving the cell to the shared memory. Pre-pended or post-pended bytes may also be added or retrieved during this time. The output ports are polled at the same time to determine when to send new cells to the Output SAMs. The cell lengths of the input ports do not need to be the same as the output port cell lengths, although all input ports and output ports respectively must be configured to the same cell length. Please refer to the SwichStar User Manual for additional feature details and implementation information. The IDT77V400 is fully 3.3V LVTTL compatible, and is packaged in an 208-pin Plastic Quad Flatpack (PQFP) and a 256-ball BGA.
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March 31, 2001
IDT77V400
SBYTE Config. Cntl. Nibble Counters Pointer Decode + Control Config. OFRM and OCLK Control
8 4 4 4 4 8 8 8
OCLK0-7
OFRM0-7 OP0D0-3 OP1D0-3 OP2D0-3 OP3D0-3 OP4D0-3 OP5D0-3 OP6D0-3 OP7D0-3
Output SAM Port 0
4
4
4
Output Latches and Buffers
4 4 4 4 4
Output SAM Port 6
4
4
4
4
Output SAM Port 7
1
4
Cntl. Output Header Output Edit Buffer
Buffer Memory Random Access Cell Memory (8192 ATM Cells) Addr
Input 1 Edit Buffer Cntl.
4
Memory Control Logic
Refresh Control
CRC Logic
IP0D0-3 IP1D0-3 IP2D0-3 IP3D0-3 IP4D0-3 IP5D0-3 IP6D0-3 IP7D0-3
4 4 4 4 4 4 4 4 4 4 8 4 4 4
Input SAM Port 0
Edit Buffer Control Mode Control and CRC Error Register IOD0-31
Input Latches and Buffers
4 4 4
Input SAM Port 1
Input SAM Port 7 Port Status
Status Register Config. Configuration Register
ICLK0-7
8
IFRM0-7
IFRM and ICLK Control
Nibble Counters, Pointer Decode + Control
Control Interface and Command Control Config. ABYTE Config.
4 6 32
CTLEN
CS
SCLK OE
CMD0-5
CRCERR
3606 drw 02
RESET
ADDR0-3
IOD0-31
Figure 2 Functional Block Diagram
INPUT TRANSFER BUS Bits 0-71 (from ISAM) OUTPUT DRAM BUS Bits 0-71 OUTPUT TRANSFER BUS Bits 0-71 (to OSAM)
To DRAM
INPUT EDIT BUFFER
.
8 OR - P/P OR - HEADER 8 32 32 XOR
BYTE byte 1
CLEAR byte 2 byte 3 [second word] HEC 72
byte 0
BYTE-PUT-PROTECT [first word] 32 CRC GEN 8 MUX
OUTPUT EDIT BUFFER
[first word] 32 MUX [second word] 32 HEC 8
32
32
8
CRC GEN
COMPARE 32 CRC error
32
IOD BUS Bits 0 - 31
3606 drw 03
Figure 3 Input and Output Edit Buffer Block Diagram
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March 31, 2001
IDT77V400
Package Diagram
All VCC/VCCQ pins must be connected to power supply. All VSS pins must be connected to ground supply. Package body is approximately 28mm x 28mm x 3.4mm.
VCCQ SBYTE ABYTE CRCERR VCC VSS IP6D0 IP6D1 IP6D2 IP6D3 IP4D0 IP4D1 IP4D2 IP4D3 VSS VCC IP2D0 IP2D1 IP2D2 IP2D3 IP0D0 IP0D1 IP0D2 IP0D3 VCC VSS IFRM7 IFRM6 IFRM5 IFRM4 IFRM3 IFRM2 IFRM1 IFRM0 ICLK7 ICLK6 ICLK5 ICLK4 ICLK3 ICLK2 ICLK1 ICLK0 RESET VCC VSS IP1D0 IP1D1 IP1D2 IP1D3 NC NC NC
NC VCC VSS VSS IOD0 IOD1 IOD2 IOD3 IOD4 IOD5 IOD6 IOD7 IOD8 IOD9 VCC VCC IOD10 IOD11 IOD12 IOD13 IOD14 IOD15 IOD16 IOD17 IOD18 IOD19 IOD20 VSS VSS IOD21 IOD22 IOD23 IOD24 IOD25 IOD26 IOD27 IOD28 IOD29 IOD30 IOD31 VCC VCC VSS VSS OP0D3 OP0D2 OP0D1 OP0D0 VCC VCC VSS NC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52
208 207 206 205 204 203 202 201 200 199 198 197 196 195 194 193 192 191 190 189 188 187 186 185 184 183 182 181 180 179 178 177 176 175 174 173 172 171 170 169 168 167 166 165 164 163 162 161 160 159 158 157
IDT77V400DS DS208-11 208-Pin PQFP Top View2
NC NC VCCQ VCC OP2D3 OP2D2 OP2D1 OP2D0 VSS VSS OP4D3 OP4D2 OP4D1 OP4D0 VCC VCC OP6D3 OP6D2 OP6D1 OP6D0 VSS OFRM0 OFRM1 OFRM2 OFRM3 OFRM4 OFRM5 OFRM6 OFRM7 VSS VCC VCC VSS OCLK0 OCLK1 OCLK2 OCLK3 OCLK4 OCLK5 OCLK6 OCLK7 CTLEN OE VSS OP7D3 OP7D2 OP7D1 OP7D0 VCC VCC VSS NC
53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104
156 155 154 153 152 151 150 149 148 147 146 145 144 143 142 141 140 139 138 137 136 135 134 133 132 131 130 129 128 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105
NC VSS VCC IP3D0 IP3D1 IP3D2 IP3D3 IP5D0 IP5D1 IP5D2 IP5D3 IP7D0 IP7D1 IP7D2 IP7D3 VSS VCC CS CMD5 CMD4 CMD3 CMD2 CMD1 CMD0 SCLK ADDR3 ADDR2 ADDR1 ADDR0 VSS VCC VSS OP1D0 OP1D1 OP1D2 OP1D3 VCC VCC OP3D0 OP3D1 OP3D2 OP3D3 VSS VSS OP5D0 OP5D1 OP5D2 OP5D3 VCC VCCQ NC NC
3606 drw 04
1 This package code is used to reference the package diagram. 2
This text does not indicate orientation of the actual part marking.
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IDT77V400
Package Diagram(1,2,3) BC256-1 BGA
A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16
ABYTE C R C E R R IP6D1
B1 B2 B3
IP6D3 IP4D2 IP2D1
B4 B5 B6
IP0D0 IP0D3 IFRM4 IFRM2 ICLK7 ICLK4 ICLK1 RESET IP1D1 IP3D0
B7 B8 B9 B10 B11 B12 B13 B14 B15 B16
IOD1 SBYTE IP6D0 IP6D2 IP4D1 IP2D0
C1 C2 C3 C4 C5 C6
IP2D3 IP0D2 IFRM5 IFRM1 ICLK6 ICLK3 ICLK0 IP1D0
C7 C8 C9 C10 C11 C12 C13 C14
IP1D3 IP3D1
C15 C16
IOD2
D1
IOD3
D2
IOD0 IP4D0 IP4D3 IP2D2 IP0D1 IFRM7 IFRM6 IFRM3 IFRM0 ICLK5 ICLK2 IP1D2 IP3D2 IP3D3
D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 D13 D14 D15 D16
IOD6
E1
IOD4
E2
IOD5
E3
VCC
E4
VCC
E5
VCC
E6
VCC
E7
VCC
E8
VCC
E9
VCC
E10
VCC
E11
VCC
E12
VCC
E13
IP5D2 IP5D1 IP5D0
E14 E15 E16
IOD8
F1
IOD7
F2
IOD9
F3
VCC
F4
VCC
F5
VCC
F6
VSS
F7
VSS
F8
VSS
F9
VSS
F10
VCC
F11
VCC
F12
VCC
F13
IP7D1 IP5D3 IP7D0
F14 F15 F16
IOD11 IOD10 IOD12
G1 G2 G3
VCC
G4
VCC
G5
VSS
G6
VSS
G7
VSS
G8
VSS
G9
VSS
G10
VSS
G11
VCC
G12
VCC
G13
CS
G14
IP7D2 IP7D3
G15 G16
IOD14 IOD13 IOD15
H1 H2 H3
VCC
H4
VSS
H5
VSS
H6
VSS
H7
VSS
H8
VSS
H9
VSS
H10
VSS
H11
VSS
H12
VCC CMD3 CMD5 CMD4
H13 H14 H15 H16
IOD17 IOD16 IOD18
J1 J2 J3
VCC
J4
VSS
J5
VSS
J6
VSS
J7
VSS
J8
VSS
J9
VSS
J10
VSS
J11
VSS
J12
VCC
J13
CMD0 CMD2 CMD1
J14 J15 J16
IOD20 IOD21 IOD19
K1 K2 K3
VCC
K4
VSS
K5
VSS
K6
VSS
K7
VSS
K8
VSS
K9
VSS
K10
VSS
K11
VSS
K12
VCC
K13
SCLK ADDR2 ADDR3
K14 K15 K16
IOD23 IOD24 IOD22
L1 L2 L3
VCC
L4
VSS
L5
VSS
L6
VSS
L7
VSS
L8
VSS
L9
VSS
L10
VSS
L11
VSS
L12
VCC ADDR0 OP1D0 ADDR1
L13 L14 L15 L16
IOD26 IOD27 IOD25
M1 M2 M3
VCC
M4
VCC
M5
VSS
M6
VSS
M7
VSS
M8
VSS
M9
VSS
M10
VSS
M11
VCC
M12
VCC OP1D2 OP1D3 OP1D1
M13 M14 M15 M16
IOD29 IOD30 IOD28
N1 N2 N3
VCC
N4
VCC
N5
VCC
N6
VSS
N7
VSS
N8
VSS
N9
VSS
N10
VCC
N11
VCC
N12
VCC OP3D1 OP3D2 OP3D0
N13 N14 N15 N16
OP0D3 OP0D2 IOD31
P1 P2 P3
VCC
P4
VCC
P5
VCC
P6
VCC
P7
VCC
P8
VCC
P9
VCC
P10
VCC
P11
VCC
P12
VCC OP5D0 OP5D1 OP3D3
P13 P14 P15 P16
OP0D1 OP0D0
R1 R2
NC
R3
OP2D0 OP4D0 OP6D1 OFRM1 OFRM4 OFRM5 OCLK0 OCLK3 OCLK6
R4 R5 R6 R7 R8 R9 R10 R11 R12
OE
R13
NC
R14
OP5D3 OP5D2
R15 R16
NC
T1
NC
T2
OP2D3 OP2D1 OP4D2 OP6D3 OP6D0 OFRM2 OFRM7 OCLK2 OCLK5
T3 T4 T5 T6 T7 T8 T9 T10 T11
C T LE N OP7D3 OP7D0
T12 T13 T14
NC
T15
NC
T16
,
NC
NC
OP2D2 OP4D3 OP4D1 OP6D2 OFRM0 OFRM3 OFRM6 OCLK1 OCLK4 OCLK7 OP7D2 OP7D1
NC
NC
3606 drw 04a
Note:
1. All VCC pins must be connected to power supply. 2. All VSS pins must be connected to ground supply. 3. Package body is approximately 17mm x 17mm x 1.4mm.
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IDT77V400
Pin Description - PQFP Package
Pin Number 132 Symbol SCLK I System clock: All bus control signals (CMD0-5, CS, IOD0-31, CRCERR) except OE are synchronous with respect to SCLK. Control commands are registered on the positive edge of SCLK. The SCLK period must be less than or equal to 200ns during normal operation. Data Port signals are asynchronous with respect to SCLK. 139 133-138 95 CS CMD0-5 OE I I I Chip Select: Synchronous input which must be LOW at the rising edge of SCLK to enable the Command Bus CMD0-5. Instructions are a NOP when CS is HIGH at the SCLK positive edge. Command Bus: Synchronized to SCLK, instructions to be executed by the memory are transferred across this 6-bit bus. CMD5 is the MSb of the Command Bus. Output Enable: Asynchronous input that enables all outputs when asserted LOW. All outputs are High-Z when OE is HIGH. IOD0-31 and CRCERR may also be set to High-Z by a HIGH CTLEN bit in the configuration register or a HIGH CTLEN pin. Reset: When asserted HIGH, the signal asynchronously allows the initialization of the registers and internal signals of the IDT77V400. RESET should be asserted HIGH and OE should be held HIGH upon power-up for the external controller to execute the initialization and insure proper system operation. Chip Address: All ADDR inputs must OR the address in the configuration register bits 26-29 and then must match 1OD13-16 one cycle after the Store or Load command for selection to allow a Store or Load memory cycle to be executed (full flag is cleared regardless of match, and empty must match before clear). ADDR3 is the MSb of the device address bits. Control Data Bus: Synchronous with SCLK. Used for external data transfer for the header pre/post-pend bytes, configuration register error and status registers, and the cell memory address. IOD31 is the MSb of the Control Data Bus. Cyclical Redundancy Check Error: Synchronous output on the rising edge of SCLK. CRCERR asserted LOW after a Header with CRC operation indicates that a CRC error has occurred on the previous header. Input Port Clock: Synchronizes the input data IPxD(0-3) and IFRMx signal associated with the input data port on the positive clock edge. Each ICLKx is independent of the other seven ICLKs and SCLK. The ICLKs used are determined by the configuration register initialization (see Port Configuration Code Table). The inputting of a cell may be halted by stopping ICLKx. Input Frame: Synchronous input registered on the rising edge of ICLKx. When asserted HIGH this signal denotes the beginning of an input cell for the associated input port. IFRMs used are determined by the configuration register during initialization (see Port Configuration Code Table). Input Data: Eight 4-bit input ports. Synchronous with the rising edge of ICLK for the associated data port. IPxD(0-3) can be assigned to different ICLKs and IFRMs via the configuration register during initialization. The ports may be combined in groups to increase bandwidth by factors of 155Mbps (see Port Configuration Code Table). IPxD3 is the MSb of the nibble. Example: IP0D3 is the MSb for port 0. Output Clock: Synchronizes the output data OPxD(0-3) and OFRMx signal associated output data port on the positive clock edge. Each OCLK is independent of the other seven OCLKs and SCLK. OCLKs used are determined by the port configuration register during initialization (see Port Configuration Code Table). The transmission of a cell may be halted by stopping OCLKx. Output Frame: Synchronous output on the rising edge of OCLK. The 77V400 marks the beginning of an output cell by taking OFRM HIGH on the rising edge of OCLK. The output SAM nibble counter loads the start byte address from the configuration register when a HIGH signal is sensed at the OFRM pin, thus re-synchronizing other chips connected to the OFRM bus. OFRM is asserted HIGH one OCLK cycle prior to the first nibble of the cell being output from the IDT77V400. OFRMs used are determined by the configuration register initialization (see Port Configuration Code Table). During cell bus operations, the OFRM1-7 are redefined as CBUS1-7 for arbitration (there is no CBUS0). Output Data: Eight 4-bit output ports. Synchronous with the rising edge of OCLK for the associated data port. OPxD(03) can be assigned to different OCLKs and OFRMs via the configuration register. The 4 bit ports may be combined in groups to increase the bandwidth by factors of 155Mbps (see Port Configuration Code Table). OPxD3 is the MSb of the nibble. Example: IP0D3 is the MSb for port 0. Type Description
166
RESET
I
128-131
ADDR0-3
I
5-14, 17-27, 30-40 205 167-174
IOD0-31 CRCERR ICLK0-7
I/O O I
175-182
IFRM0-7
I
185-188, 160-163, 189-192, 150-153, 195-198, 146-149, 199-202, 142-145 86-93
IP(0-7)D(0-3) I
OCLK0-7
I
74-81
OFRM0-7
I/O
45-48, 121-124, 57- OP(0-7)D(0-3) O 60, 115-118, 63-66, 109-112, 69-72, 97100
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March 31, 2001
IDT77V400 Pin Number 94 206 Symbol CTLEN ABYTE I I Type Description Control Enable: When asserted LOW, with OE LOW and the CTLEN bit set LOW in the configuration register, this pin asynchronously enables all Control interface outputs. If CTLEN is HIGH all control interface outputs will be High-Z. Add Byte to Input cell: Asynchronous DC signal. If an input port is in a 4-bit or 8-bit DPI mode and ABYTE is asserted HIGH, a dummy byte will be inserted in the ninth byte position (after the HEC byte) to support systems requiring a byte between the last header byte and the payload (otherwise ignored). Not intended for dynamic cycling or operation. Subtract Byte to Output cell: Asynchronous DC signal. When and SBYTE is asserted HIGH, the dummy byte in the ninth byte position (after the HEC byte) will be removed prior to transmission to support output port 4-bit and 8-bit DPI modes (otherwise ignored). Not intended for dynamic cycling or operation. No Connect Power Supply (+3.3V 300mV)
207
SBYTE
I
1, 52-54, 104-06, 156-59
NC
-- Power
2, 15-16, 41-42, 49- VCC 50, 56, 67-68, 83-84, 101-02, 108, 119-20, 126, 140, 154, 165, 184, 193, 204 55, 107, 208 VCCQ
Power Power
Output Power Supply (+3.3 300mV) Ground
3-4, 28-29, 43-44, VSS 51, 61-62, 73, 82, 85, 96, 103, 113-14, 125, 127, 141, 155, 164, 183, 194, 203
Pin Description - BGA Package
Pin Number J14 Symbol SCLK I Type Description System clock: All bus control signals (CMD0-5, CS, IOD0-31, CRCERR) except OE are synchronous with respect to SCLK. Control commands are registered on the positive edge of SCLK. The SCLK period must be less than or equal to 200ns during normal operation. Data Port signals are asynchronous with respect to SCLK. Chip Select: Synchronous input which must be LOW at the rising edge of SCLK to enable the Command Bus CMD0-5. Instructions are a NOP when CS is HIGH at the SCLK positive edge. Command Bus: Synchronized to SCLK, instructions to be executed by the memory are transferred across this 6-bit bus. CMD5 is the MSb of the Command Bus. Output Enable: Asynchronous input that enables all outputs when asserted LOW. All outputs are High-Z when OE is HIGH. IOD0-31 and CRCERR may also be set to High-Z by a HIGH CTLEN bit in the configuration register or a HIGH CTLEN pin. Reset: When asserted HIGH, the signal asynchronously allows the initialization of the registers and internal signals of the IDT77V400. RESET should be asserted HIGH and OE should be held HIGH upon power-up for the external controller to execute the initialization and insure proper system operation. Chip Address: All ADDR inputs must OR the address in the configuration register bits 26-29 and then must match 1OD13-16 one cycle after the Store or Load command for selection to allow a Store or Load memory cycle to be executed (full flag is cleared regardless of match, and empty must match before clear). ADDR3 is the MSb of the device address bits. Control Data Bus: Synchronous with SCLK. Used for external data transfer for the header pre/post-pend bytes, configuration register error and status registers, and the cell memory address. IOD31 is the MSb of the Control Data Bus.
F14 G14-16, H14-16 P13
CS CMD0-5 OE
I I I
A14
RESET
I
J15-16, K14, K16
ADDR0-3
I
B1, C1-3, D1-3,E1-3, IOD0-31 F1-3, G1-3, H1-3, J1-3, K1-3, L1-3, M13, N3 A2 CRCERR
I/O
O
Cyclical Redundancy Check Error: Synchronous output on the rising edge of SCLK.CRCERR asserted LOW after a Header with CRC operation indicates that a CRC error has occurred on the previous header.
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IDT77V400 Pin Number A11-13, B11-13, C12-13 Symbol ICLK0-7 I Type Description Input Port Clock: Synchronizes the input data IPxD(0-3) and IFRMx signal associated with the input data port on the positive clock edge. Each ICLKx is independent of the other seven ICLKs and SCLK. The ICLKs used are determined by the configuration register initialization (see Port Configuration Code Table). The inputting of a cell may be halted by stopping ICLKx. Input Frame: Synchronous input registered on the rising edge of ICLKx. When asserted HIGH this signal denotes the beginning of an input cell for the associated input port. IFRMs used are determined by the configuration register during initialization (see Port Configuration Code Table). Input Data: Eight 4-bit input ports. Synchronous with the rising edge of ICLK for the associated data port. IPxD(0-3) can be assigned to different ICLKs and IFRMs via the configuration register during initialization. The ports may be combined in groups to increase bandwidth by factors of 155Mbps (see Port Configuration Code Table). IPxD3 is the MSb of the nibble. Example: IP0D3 is the MSb for port 0. Output Clock: Synchronizes the output data OPxD(0-3) and OFRMx signal associated output data port on the positive clock edge. Each OCLK is independent of the other seven OCLKs and SCLK. OCLKs used are determined by the port configuration register during initialization (see Port Configuration Code Table). The transmission of a cell may be halted by stopping oclkx. Output Frame: Synchronous output on the rising edge of OCLK. The 77V400 marks the beginning of an output cell by taking OFRM HIGH on the rising edge of OCLK. The output SAM nibble counter loads the start byte address from the configuration register when a HIGH signal is sensed at the OFRM pin, thus re-synchronizing other chips connected to the OFRM bus. OFRM is asserted HIGH one OCLK cycle prior to the first nibble of the cell being output from the IDT77V400. OFRMs used are determined by the configuration register initialization (see Port Configuration Code Table). During cell bus operations, the OFRM1-7 are redefined as CBUS1-7 for arbitration (there is no CBUS0). Output Data: Eight 4-bit output ports. Synchronous with the rising edge of OCLK for the associated data port. OPxD(03) can be assigned to different OCLKs and OFRMs via the configuration register. The 4 bit ports may be combined in groups to increase the bandwidth by factors of 155Mbps (see Port Configuration Code Table). OPxD3 is the MSb of the nibble. Example: IP0D3 is the MSb for port 0. Control Enable: When asserted LOW, with OE LOW and the CTLEN bit set LOW in the configuration register, this pin asynchronously enables all Control interface outputs. If CTLEN is HIGH all control interface outputs will be High-Z. Add Byte to Input cell: Asynchronous DC signal. If an input port is in a 4-bit or 8-bit DPI mode and ABYTE is asserted HIGH, a dummy byte will be inserted in the ninth byte position (after the HEC byte) to support systems requiring a byte between the last header byte and the payload (otherwise ignored). Not intended for dynamic cycling or operation. Subtract Byte to Output cell: Asynchronous DC signal. When and SBYTE is asserted HIGH, the dummy byte in the ninth byte position (after the HEC byte) will be removed prior to transmission to support output port 4-bit and 8-bit DPI modes (otherwise ignored). Not intended for dynamic cycling or operation. No Connect Power Supply (+3.3V +300mV)
A9-10, B9-10,C8-11 IFRM0-7
I
A3-8, A15-16, B3-8, IP(0-7)D(0-3) I B14-16, C4-7, C14-16, D14-16, E14-16, F15-16 P10-12, R10-11, T10-12 OCLK0-7 I
P7-9, R8-9, T7-9
OFRM0-7
I/O
K15, L14-16,M14-16, OP(0-7)D(0-3) O N1-2, N14-16, P1-2, P4-6, P15-16, R3-7, R13-14, T3-6,T13-14 R12 A1 CTLEN ABYTE I I
B2
SBYTE
I
P3, P14, R1-2, R15- NC 16, T1-2, T15-16 D4-13, E4-6, E11-13, VCC F4-5, F12-13, G4, G13, H4, H13, J4, J13, K4, K13, L4-5, L12-13, M4-6, M1113, N4-13 E7-10, F6-11, G5-12, VSS H5-12, J5-12, K5-12, L6-11, M7-10
-- Power
Power
Ground
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Absolute Maximum Ratings
Symbol VTERM2 TBIAS TSTG IOUT
1. Stresses
Rating1 Terminal Voltage with Respect to VSS Temperature Under Bias Storage Temperature DC Output Current
Commercial -0.5 to +3.9 -55 to +125 -55 to +125 50 V C C mA
Unit
greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.
2. VTERM must not exceed Vcc + 0.3V for more than 25% of the cycle time or 10ns maximum, and is limited to 20mA for the period of VTERM Vcc + 0.3V.
Maximum Operating Temperature and Supply Voltage
Grade Commercial Industrial
1.
Ambient Temperature1 0C to +70C -40C to +85C
GND 0V 0V
Vcc 3.3V 300mV 3.3V 300mV
This is the parameter TA. PQFP ONLY
(TA 1.0MHz Capacitance (TA = +25C, f = 1.0MHz)
Symbol CIN COUT3
1.
Parameter1 Input Capacitance Output Capacitance
Conditions2 VIN = 3dV VOUT = 3dV 9
Max.
Unit pF pF
10
These parameters are determined by device characterization, but are not production tested. COUT also references CI/O
2. 3dV references the interpolated capacitance when the input and output switch from 0V to 3V or from 3V to 0V. 3.
Recommended DC Operating Conditions
Symbol VCC VSS VIH VIL
1. 2.
Parameter Supply Voltage Ground Input High Voltage Input Low Voltage 3.0 0 2.0
Min. 3.3 0 -- --
Typ. 3.6 0
Max. V V V V
Unit
Vcc + 0.31, 2 0.8
-0.33
VIL -1.5V for pulse width less than 10ns. VTERM must not exceed Vcc + 0.3V or Vss - 0.3V.
3. VTERM must not exceed Vcc + 0.3V for more than 25% of the cycle time or 10ns maximum, and is limited to 20mA for the period of VTERM Vcc + 0.3V.
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DC Electrical Characteristics Over the Operating Temperature and Supply (VCC Voltage Range (VCC = 3.3V 0.3V)
77V400S Symbol |ILI| |ILO| VOL VOH Parameter Input Leakage Current Output Leakage Current Output Low Voltage Output High Voltage Test Conditions VCC = 3.6V, VIN = 0V to VCC CS = VIH, VOUT = 0V to VCC, OE = VIH, CTLEN = VIH IOL = +4mA IOH = -4mA Min. ___ ___ ___ 2.4 Max. 10 10 0.4 ___ Unit A A V V
DC Electrical Characteristics Over the Operating Temperature and Supply (VCC Voltage Range (VCC = 3.3V 0.3V)
77V400S156DSI Symbol ICC
1.
77V400S156DS Typ. 100 Max. 160 Unit mA
Parameter
Test Conditions
Typ. 100
Max. 180
Operating Current VCC = 3.6V, CS = VIL, OE = VIH, CTLEN = VIH, RESET = VIL or VIH, f = fmax1
At f = fmax SCLK, ICLK, and OCLK are cycling at their maximum frequency and all inputs are cycling at 1/tCYC1, using AC input levels of VSS to 3.0V.
AC Test Conditions
Input Pulse Levels Input Rise/Fall Times Input Timing Reference Levels Output Reference Levels Output Load Vss to 3.0V 3ns Max. 1.5V 1.5V Figures 4 and 5
3.3V 3.3V
590 DATAOUT 435 50pF DATAOUT 435
590
5pF*
3606 drw 05
3606 drw 06
Figure 4 AC Output Test Load
Figure 5 Output Test Load (for High-Impedance parameters) * Including scope and jig.
AC Electrical Characteristics Over the Operating Temperature Range (VCC (Read and Write Cycle Timing) (VCC = 3.3V 0.3V)
77V400S156 Com'l & Ind Symbol tCYC tCH tCL tR tF tSC Parameter System Clock Cycle Time System Clock High Time System Clock Low Time Clock Rise Time Clock Fall Time CS Setup Time to SCLK High Min. 25 10 10 -- -- 4 Max. -- -- -- 3 3 -- Unit ns ns ns ns ns ns
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77V400S156 Com'l & Ind Symbol tHC tSCM tHCM tSIO tHIO tCDIO tDCIO tCYCI1 tCHI tCLI tSIF tHIF tSID tHID tOE tOHZ tOLZ tRST tRSTL tCTEN tCTHZ tCTLZ tCDCR tDCCR tCYCO tCHO tCLO tSOF tHOF tCDOF tCDOF tCDOD tDCOD tCKHZ tCKLZ
1.
Parameter CS Hold Time after SCLK High CMD Setup Time to SCLK High CMD Hold Time after SCLK High IOD Setup Time to SCLK High IOD Hold Time after SCLK High SCLK to IOD Valid IOD Output Hold after SCLK High ICLK Cycle Time ICLK High Time ICLK Low Time IFRM Setup Time to ICLK High IFRM Hold Time after ICLK High ID Setup Time to ICLK High ID Hold Time after ICLK High OE Low to Data Valid OE High to Output High-Z RESET High Pulse Width
2
Min. 1 4 1 4 1 -- 2 23 9 9 4 1 4 1 -- -- 2 20 10 -- -- 2 -- 2 23 9 9 4 1 -- 2 -- 2 -- 2
Max. -- -- -- -- -- 18 -- -- -- -- -- -- -- -- 15 15 -- -- -- 15 15 -- 18 -- -- -- -- -- -- 18 -- 18 -- 15 --
Unit ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns
OE Low to Output Low-Z2
3
RESET Low to SCLK High CTLEN Low to Data Valid CTLEN High to Output High-Z2 CTLEN Low to Output Low-Z2 SCLK to CRCERR Valid (1 cycle delay) CRCERR Output Hold after SCLK High OCLK Cycle OCLK High Time OCLK Low Time OFRM Setup Time to OCLK High OFRM Hold Time after OCLK High OCLK to OFRM Valid OFRM Output Hold after OCLK High OCLK to OPxD Valid OD Output Hold after OCLK High SCLK High to Output High-Z2 SCLK High to Output Low-Z2
ICLK frequency must not exceed SCLK frequency. 2. Transition is measured +/-200mV from Low or High impedance voltage with the Output Test Load (Figure 2). This parameter is guaranteed by device characterization, but is not production tested 3. Although RESET is an asynchronous function, it must be centered around the SCLK so that it will be Low 10ns prior to the next SCLK rising edge to prevent initiating another Reset operation.
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Basic Functional Description
Input data is received by the Switching Memory via the four-bit input data ports (IPxD). Each input port is configured as a double buffer with SRAM storage for two complete ATM cells. Each input port also has an independent input clock, (ICLK) and an input framing signal (IFRM). The external controller may poll the internal status register through the Control Data Bus (IOD Bus) to determine if any of the eight input SAMs (ISAMx) are full and any of the eight Output SAMs (OSAMx) are empty. The status register accessed through the IOD Bus also provides ISAM error status information. If an error is detected for any of the ISAMs, the error register can then be read through the IOD Bus to further determine the presence of short or long cells or SAM overflow. OFRM may also be used to monitor OSAM status. Upon a Store command, data from the selected ISAM is transferred to the cell memory at the location selected by the controller on the IOD Bus. Similarly, on a Load command data from the specified cell memory location is transferred to the OSAMx specified by the controller on the IOD Bus. The output ports are also individually double buffered and each output port can hold up to two complete ATM cells. A cell output ready signals the status register to allow the loading of the second buffer to begin while the first buffer begins to transmit via the 4-bit output port. Each output port has an independent clock (OCLKx) and output framing signal (OFRMx). Once a cell has been received in the ISAM, the header bytes and the pre/post-pend bytes, if enabled, may be examined and modified via the IOD bus. The CRC byte may also be modified, although it is modified internally to the switching memory and is not read on the IOD Bus. The IOD Bus is also used to set the internal configuration register at initialization, determining the input and output cell length and the input and output port configurations. The input edit buffer provides the means to modify the cell header or pre/post-pend data of a cell in the ISAM before storing the cell in the Memory portion of the IDT77V400. The command selected (GHE or GPE, for example) will determine which bits are transferred to the control logic across the IOD bus. Two features are included to eliminate the need for an extra step in the edit sequences of the input edit buffer. A Byte Protect function, which prevents a PUT instruction from changing any protected bytes stored in the input edit buffer, and a Clear Byte function, which clears bytes in the input edit buffer in preparation for ORing at the output, are described in the Input Ports section of this data sheet. See the Input and Output Edit Buffer Block Diagram for additional details of the functionality and data path of this circuitry. The output edit buffer provides a means to modify the cell contents at the last possible moment prior to transmission of a cell out an output port. The output edit buffer provides data to an OR function between the Buffer Memory and the OSAMs, allowing the IOD bus to set selected bits in the cell header and pre/post pend data immediately before transmission. The following basic functional description is divided into three sections--the control interface, the input ports, and the output ports. For clarity we will use an 8x8 Switching Memory configuration, with each
port being 4-bits wide. Higher port bandwidth can be obtained by combining multiple 4-bit wide ports into 8, 16, or 32-bit wide ports during device initialization and configuration (see Configuration Codes Table).
Control Interface
The control interface consists of 48 pins. The 32-bit control data bus (IOD0-31) is used to transfer address, data, and header information. The 6-bit command bus (CMD0-5) is used when CS is LOW to issue commands to the Switching Memory. When CS is HIGH, all issued commands become invalid (no operation is performed) (see the Control Interface Command Table for a listing of commands). The CRCERR output pin indicates that a CRC error has occurred on the last header when asserted LOW. The asynchronous OE input pin is the master output enable for all outputs; all output drivers will be in a high-impedance state when OE is driven HIGH. Upon power-up initialization the OE pin should be held HIGH and the RESET pin should be asserted HIGH to allow proper device initialization by the controller. The asynchronous CTLEN input pin controls the Control Interface outputs. When the CTLEN pin is LOW, the OE pin is LOW, and the CTLEN bit of the configuration register is LOW, the Control Interface outputs are enabled. If the CTLEN pin or the CTLEN bit of the configuration register is HIGH, all control Interface outputs will be in the High-Z state (see Control Enable Timing Waveform). The ADDR0-3 pins are used in conjunction with the configuration register to selectively enable Switching Memories that are sharing a control bus. All inputs and outputs of the control interface, with the exception of OE, RESET, and ADDR0-3 are synchronous with the system clock input (SCLK). As shown in the Control Interface Timing Waveform, the control interface provides access to five internal registers -- the configuration register, the status register, the error register, the input edit buffers, and the output edit buffers. The control interface is implemented as a pipeline. Commands are registered on the rising edge of SCLK, and in general, the Switching Memory either expects data or will output data on IOD0-31 on the subsequent SCLK rising edge. The Control Inter-face Protocol Waveform shows an example of this protocol for the GHI (Get Header from ISAMx) and GST (Get Status Register) instructions. The bus width and clock rate of the control interface has been carefully matched to the internal bandwidth of the Switching Memory, and to the control requirements for high-speed multiport traffic. Additionally, many of the commands which require multiple SCLK cycles to execute, allow other commands to overlap the command cycles. In this manner, the commands can be pipelined. The control interface of the Switching Memory provides sufficient bandwidth to keep pace with the control operations required of all sixteen data ports, the memory refresh activities, and the other associated overhead.
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Control Interface Commands
COMMAND Bus Bit (CMD5:0) MSb LSb Command1 GPIx GHIx GPE GHE GST GER STEx STIx LDOx PPE PHE PHEC REF LDC OPE OHE OHEC NOP
1. 2.
Command Description Get Pre/Post Pend Data from ISAMx2 Get Header from ISAMx2 Get Pre/Post Pend Data from Edit Buffer Get Header from Edit Buffer Get ISAM and OSAM Status Register Bits Get Error Register Bits Store Cell in ISAMx2 and Input Edit Buffer in Memory Store Cell in ISAMx2 in Memory Load Cell from Memory into OSAMx2 Put new Pre/Post Pend in Input Edit Buffer Put new Header in Input Edit Buffer Put new Header and new CRC byte in Input Edit Buffer Refresh Memory Load Configuration Register Put Pre/Post Pend Data in Output Edit Register Put new Header in Output Edit Register Put new Header and new CRC byte in Output Edit Register No Operation 0 0 0 0 0 0 1 1 1 1 1 1 0 1 1 1 1 1
5
4 0 0 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1
3 0 1 0 0 0 0 0 1 0 1 1 1 0 1 1 1 1 1
2 n3 n3 0 1 0 1 n3 n3 n3 0 1 1 1 0 0 1 0 1
1 n3 n3 0 0 1 1 n3 n3 n3 0 0 0 1 1 1 1 0 1 n3 n3 0 0 0 0 n3 n3 n3 0 0 1 1 0 1 0 1 1
0
CMD bus commands not defined in this table are undefined and not to be implemented. "x" represents the specific ISAM or OSAM being accessed (IP0-IP7 or OP0-OP7 respectively). 3. "n" represents the appropriate bit of the binary representation of the ISAM or OSAM being accessed (000 to 111).
Control Interface Timing Waveform
CTLEN is Low and the CTLEN bit of the configuration register (Bit 31) is LOW for this waveform.
tCYC tCH tCL SCLK tSC tHC CS tSCM CMD0-5
GET STATUS NOP
tHCM
STORE ISAM PUT HEADER GET STATUS [ AVAILABLE FOR NEXT COMMAND ]
GET HEADER
tSCM tHCM IOD0-31
1
tCDIO
tDCIO
Output Old Header Cell Addr
tCDIO
Input - 2 Input New Header
tDCIO
Output Status
tCDCR CRCERR tOLZ tOE
3606 drw 07
[ CRC ERROR = LOW ]
tOHZ OE
1All output signals except
CRCERR are controlled by OE. 2 The 13-bit cell address, 4-bit selected Switching Memory address, and the 5-bit Edit Buffer Protect and Clear control bits are valid at this time.
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Control Enable Timing Waveform
The CTLEN bit of the configuration register (Bit 31) is LOW for this waveform. If the CTLEN bit of the configuration register is set HIGH at device initialization the IOD bus will always be in input mode for multiple Switching Memory configurations.
CTLEN OE tCTEN tCTLZ IOD0-31 ENABLED
3606 drw 08
tCTHZ
Reset Waveform
Reset function can also be accomplished by holding the RESET bit [Bit 30] High on the IOD bus during a LDC (Load Configuration Register) command.
tCYC SCLK tRST 1 RESET
3606 drw 09
tRSTL 2
1
tRST must be greater than two SCLK cycles. Any glitch could cause an erroneous reset operation. 2 RESET must be Low 10ns prior to the next rising SCLK edge to insure that the Reset function is not repeated
Input Port Timing Waveform
tCYCI tCHI tCLI ICLKx
1
tSIF IFRMx
2
tHIF
tSID IPxD0-3
tHID
Nibble 1 Nibble n (Last of cell) Nibble 0
Nibble 0
Cell n
Cell n+1
3606 drw 10
1ICLK frequency must not exceed the SCLK frequency. 2 tSIF and tHIF (IFRM Setup and Hold) must be met for each ICLK rising edge for IFRM Low and High.
Output Port Timing Waveform
tCYCO tCLO tCHO OCLKx tCDOF OFRMx
1
tDCOF
1
tCDOD tDCOD OPxD0-3 tOLZ OE tOE
Nibble 0 Nibble n-2
Nibble n-1
Nibble n (Last of cell)
Nibble 0
Cell n
Cell n+1 tOHZ
3606 drw 11
1
OFRMx is actually tri-stated by the device one cycle before the end of the frame; the logic Low level is due to the recommended 5k ohm resistor on the OFRMx line.
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Input Ports
A 155Mbps input Data Path Interface (DPI) consists of six pins - four data bits (IPxD0-3), an input clock (ICLKx), and an input framing signal (IFRMx). A further definition of the DPI interface is available in Technical Note 34, available on the IDT Web Site (www.idt.com). The "x" in the signal name corresponds to a port number (0 through 7 for the 8 x 8 port configuration). IPxD0-3 and IFRMx are synchronous inputs with respect to the rising edge of ICLKx, and the ICLK frequency must not exceed the SCLK frequency. Each Input SAM (ISAMx) is double buffered, with each ISAM buffer able to store a single ATM cell of up to 56 bytes in length. The 32-bit Header and up to 32 bits of Pre-Pend and/or Post-Pend bytes may be accessed and modified via the Control Data Bus interface. The Input Port Timing Waveform assumes that the Switching Memory has been initialized and the ISAMs are empty. An active HIGH IFRMx signal indicates that the first nibble of a new cell will be received on the next rising edge of ICLKx and the cell counter is initialized. Data will be sequentially clocked into the ISAM buffer on each subsequent ICLKx rising edge after IFRMx goes LOW. The status register bit indicating ISAMx buffer is full will be set HIGH when the ISAM counter reaches the stop address. The ISAM start and stop address is programmed via the configuration register at initialization to establish the input cell length and protocol. If IFRMx input goes HIGH before the stop position address is reached, the start byte position address will be reloaded, the ISAM Full Status indicator will not be set, a Short Cell error status indicator will be set in the error register, and the cells will be overwritten. If the IFRMx does not go HIGH when the stop position address is reached, the ISAM Full status indicator and a Long Cell error status indicator will be set. A Long Cell error results in the beginning portion of the long cell being kept, the last portion being discarded, and the next cell being accepted in the other half of the ISAM on the next IFRMx HIGH. When the IFRMx input stays HIGH, the load start byte position address process will repeat for every ICLKx and the actual count will not start until IFRMx goes LOW. A subsequent cell may be input back-toback (no dead cycle on the IOD bus). In this case the IFRMx of the second cell will occur on the same ICLKx rising edge as the last data nibble of the first cell. When the control logic returns 32-bits of information across the IOD bus during a STORE command, the five most significant bits provide the Byte Edit control for the first word of the input edit buffer. These four bytes are either cleared, protected, or unaffected depending on the value of the bits IOD27-31. These five bits are updated each time a STORE command is executed. IOD31 determines if the function is clear or protect; IOD 27-30 select which bytes in the first word of the Input edit buffer are affected. The Edit Buffer Protect/Clear Codes table defines the possible combination of these bits. Each of the eight 4-bit input ports is capable of receiving 155Mbps data; however, the ports can be combined in groups of four bits to receive data rates up to 1.2Gbps. For example, four 4-bit ports can be combined to receive 622Mbps traffic. The output ports can also be combined, via the configuration register, independent of the input data ports. This allows the Switching Memory to be configured as a concentrator, expander, or cell buffer with multiple bus widths. When combining
ports, the chip is internally reconfigured to accept a single master ICLK for the grouped ports (always using the least significant ICLK/IFRM of those combined), and the data path is internally switched to correctly align the ports for CRC generation and Header/Pre-Post Pend comparison. See the Port Configuration Code Table for option definitions. By varying the input and output port options, one hundred different port configurations are available to the user to optimize design flexibility.
Output Ports
The output data ports are similar in operation to the input data ports. There are eight 155Mbps DPI ports, six pins each. Data is transmitted out the 4-bit data bus (OPxD0-3), synchronous with the output clock (OCLKx). An output framing signal (OFRMx) is provided which is also synchronous with respect to OCLKx. The output port protocol was designed to interface directly with the input port of another Switching Memory without requiring additional logic. This allows cascading of multiple Switching Memory chips to implement wider multiplexers or larger capacity cell buffers without additional logic. To facilitate cascading, OFRMx has been implemented as a tri-statable I/O, while OPxD pins are tri-statable outputs. All chip outputs can be disabled to a high impedance state by asserting the OE pin HIGH. Output ports of a single device or of multiple devices may share an output bus if they are configured in the cell bus mode, where control logic performs the arbitration between IDT77V400s, or are externally controlled via the OE. In the cell bus mode configuration, one external controller would typically drive the control interface of multiple Switching Memory chips and use the OFRMx to arbitrate the shared bus. Output SAM (OSAMx) control logic must receive a LDx (Load OSAMx) instruction from the external controller via the Command Bus to dispatch a cell. The LDx instruction initiates a cell transfer from the memory location specified on the IOD Bus to the specified OSAMx. At this point the user has the option of modifying the Header and the PrePost Pend bytes. When the output buffer has a cell loaded to send, Switching Memory will immediately assert the specific OFRMx HIGH for one OCLKx cycle prior to transmitting data. When the OFRMx is then asserted LOW, the first data nibble of the new cell will appear prior to the next rising edge of OCLKx. The output port will continue to assert OFRMx LOW (while the cell is output from OSAMx) for a minimum of two cycles before the end of the cell transmission. At that time (if in cell bus mode) OFRMx is released to a high-impedance state during the cycle before the end of the frame to allow collision free control transfer to another Switching Memory. After asserting OFRMx HIGH, the OSAMx EMPTY bit in the status register will be set, indicating that an OSAM buffer is available for a new cell to be loaded from the memory. The EMPTY bit is reset when a LDx command is performed and after the cell is transmitted. It is recommended that a pull down resistor be used on OFRMx pin to eliminate the possibility of an invalid OFRMx HIGH. The value of this pull down resistor will be determined by a specific board design or noise issues. A 5K resistor is recommended for this pull down function, although 50-100K may be sufficient in most applications.
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The OFRM pin is always monitored internally by the Switching Memory. The OFRMx output is released to a High-impedance state when it is in cell bus mode and a cell is not ready for dispatch. Upon receiving a HIGH OFRMx input, the Switching Memory will hold if a transmission was beginning. When an output port asserts OFRMx HIGH all of Switching Memories on the bus, including the transmitting Switching Memory, reset the internal start of frame count. The transmitting IDT77V400 then places the data on the output bus and all Switching Memories on the bus count to the end of the frame. If OFRMx is an output, the internal OSAMx counter is set to the starting address. The counter will count up to the stop address for each subsequent OCLKx rising edge after OFRMx goes low. In this manner, all devices sharing the output bus must be set to the same nibble count. if a switching memory receives a ldx command while any port is transmitting on the output bus, it will continue counting and wait for the stop address to be reached before asserting ofrmx and dispatching a cell. this will avoid collisions on the bus; however, it is the responsibility of the external controller to issue only one ldx command for a shared cell bus within a single cell transmit time.
Functional Waveforms
MEMORY STORE SEQUENCE MEMORY STORE CYCLE SCLK CS
1
CMD0-5
GET HEADER ISAM
STORE 4 ISAM
PUT 2 HEADER
GET STATUS
IOD0-31 IOD BUS MODE Input
Old Header
Cell 3 Address
New 2 Header
Port Status
Output
Input
Input
Output
Input
Input
Input
3606 drw 12
Figure 6 Functional Waveform - Store Instruction Sequence
1
The Memory Store Cycle requires four cycles to write the cell from the ISAM to the Buffer Memory. point in the sequence instead of the PHE command. The IOD bus would then reflect the appropriate bytes in the cell based on
2The PPE or PHEC commands can be executed at this
the command used.
3
The 13-bit cell address, 4-bit selected Switching Memory address, and 5-bit Edit Buffer Protect and Clear control bits are valid at this time. only be valid for one cycle during a Memory Store Cycle. Issuing more than one STORE ISAM will cause Buffer Memory write failure.
LOAD SEQUENCE LOAD CYCLE SCLK CS
4STORE ISAM command can
1
CMD0-5
GET HEADER
LOAD 4 OSAM Old Header
OR 2 HEADER Cell 3 Address
GET STATUS Header Data 2 Port Status
IOD0-31 IOD BUS MODE
Input
Output
Input
Input
Output
Input
Input
Input
3606 drw 13
Figure 7 Functional Waveform - Load Instruction Sequence
1
The Memory Load Cycle requires four cycles to write the cell from the Buffer Memory to the OSAM.
2The 3
OPE or OHEC commands can be executed at this point in the sequence instead of the OHE command. The IOD bus would then reflect the appropriate cell bytes based on the command used. The 13-bit cell address and 4-bit selected Switching Memory address are valid at this time OSAM command can only be valid for one cycle during a Load Sequence. Issuing more than one LOAD OSAM will cause Buffer Memory read failure.
4LOAD
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REFRESH SEQUENCE 1 REFRESH CYCLE SCLK CS
CMD0-5
REFRESH 2
GET STATUS
GET STATUS
IOD0-31 IOD BUS MODE
Port Status
Port Status
Input
Input
Input
Output
Output
Input
Input
Input
3606 drw 14
Figure 8 Functional Waveform - Refresh Sequence
1
The Refresh sequence begins with the REF command and ends when the four cycle Buffer Memory Refresh has completed. only be valid for one cycle during a Refresh Sequence. Refresh must be completed prior to another command to avoid data corruption.
2REFRESH command can
MEMORY STORE SEQUENCE n+1 MEMORY STORE SEQUENCE n MEMORY STORE CYCLE SCLK
CMD0-5
GET STATUS
GET STATUS
GET HEADER ISAM
STORE ISAM
PUT HEADER
GET STATUS
GET STATUS
GET STATUS
GET HEADER ISAM
STORE ISAM
IOD0-31
Port Status
Port Status
Old Header
Cell 2 Address
New Header
Port Status
Port Status
Port Status
Old Header
IOD BUS MODE
Output
Output
Output
Input
Input
Output
Output
Output
Output
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Figure 9 Multi-Sequence Functional Waveform Example - Idle, Memory Store, Initiate Memory Store1
1CS is 2
Low
The 13-bit cell address and 4-bit selected Switching Memory address and 5-bits Edit Buffer Protect and Clear control bits are valid at this time.
LOAD SEQUENCE n+1 LOAD SEQUENCE n LOAD CYCLE SCLK
CMD0-5
GET STATUS
GET STATUS
GET STATUS
LOAD OSAM
OR HEADER
GET STATUS
GET STATUS
LOAD OSAM
OR HEADER
IOD0-31 IOD BUS MODE
Port Status
Port Status
Port Status
Cell 2 Address
Header Data
Port Status
Port Status
Cell 2 Address
Header Data
Output
Output
Output
Input
Input
Output
Output
Input
Input
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Figure 10 Multi-Sequence Functional Waveform Example - Idle, Load, Initiate Load1
1 2
CS is Low.
The 13-bit cell address and 4-bit selected Switching Memory address are valid at this time.
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IDT77V400
LOAD SEQUENCE LOAD CYCLE MEMORY STORE SEQUENCE MEMORY STORE CYCLE SCLK
REFRESH SEQUENCE
CMD0-5
LOAD OSAM
OR HEADER
GET STATUS
GET ISAM HEADER
STORE ISAM
PUT HEADER
GET STATUS
GET STATUS
REFRESH
GET STATUS
IOD0-31 IOD BUS MODE
Cell Address
Header Data
Port Status
Old Header
Cell 2 Address
New Header
Port Status
Port Status
Port Status
Input
Input
Output
Output
Input
Input
Output
Output
Input
Output
3606 drw 17
Figure 11
1 2
Multi-Sequence Functional Waveform Example - Load, Memory Store, Initiate Refresh1
CS is Low. The 13-bit cell address and 4-bit selected Switching Memory address and 5-bits Edit Buffer Protect and Clear control bits are valid at this time.
REFRESH SEQUENCE REFRESH CYCLE MEMORY STORE SEQUENCE MEMORY STORE CYCLE SCLK
LOAD SEQUENCE
CMD0-5
REFRESH
GET STATUS
GET STATUS
GET ISAM HEADER
STORE ISAM
PUT HEADER
GET STATUS
GET STATUS
LOAD OSAM
OR HEADER
IOD0-31
Port Status
Port Status
Old Header
Cell 2 Address
New Header
Port Status
Port Status
Cell 3 Address
Header Data
IOD BUS MODE
Input
Output
Output
Output
Input
Input
Output
Output
Input
Input
3606 drw 18
Figure 12
1
Multi - Sequence Functional Waveform Example - Refresh, Memory Store, Initiate Load1
CS is Low. and 4-bit selected Switching Memory address and 5-bit Edit Buffer Protect and Clear control bits are valid at this time. The 13-bit cell address and 4-bit selected Switching Memory address are valid at this time; Clear control bits are ignored during the Load sequence.
2The 13-bit cell address 3
Configuration Register Definition
Register Bits1 0-3 4-7 8-10 11-16 17-19 20-25 26-29 30 31
1. 2.
Field Name ISAM Configuration OSAM Configuration ISAM Start ISAM Stop OSAM Start OSAM Stop Chip Address Reset2 CTLEN
Field Description Four bit configuration code for the input ports as defined in the Table of configuration codes. Four bit configuration code for the output ports as defined in the Table of configuration codes. Three bit starting byte position for the ISAMs. Six bit stop byte position for the ISAMs. Three starting byte position for the OSAMs. Six bit stop byte position for the OSAMs. Four bit field for multiple device configurations. One bit used to reset the status and output waiting bits. One bit used for the Control Interface outputs during parallel operation.
Configuration Register Bit number corresponds to the same bit position on the IOD bus. Bit 0 is the LSb bit; bit 31 is the MSb. This bit is not stored in the Configuration Register. It must be asserted on the IOD bus to generate asynchronous reset operation.
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IDT77V400
Port Configuration Codes
Config Code1,2 MSb 0000 0001 00103 0011 01003 0101 01103 0111 10003 1001 10103 1011 1103 1101 1110 1111
1. Configuration
Port Configuration 0 4 bit 1 4 bit 2 4 bit 4 bit 4 bit 3 4 bit 4 bit 4 bit 4 4 bit 4 bit 4 bit 4 bit 5 4 bit 4 bit 4 bit 4 bit 4 bit 6 4 bit 4 bit 7 4 bit 4 bit 8 bit, CLK/FRM 6 4 bit 8 bit, CLK/FRM 6 4 bit 4 bit 8 bit, CLK/FRM 6 8 bit, CLK/FRM 6 16 bit, CKL/FRM 4 4 bit 4 bit 4 bit 4 bit
LSb
8 bit, CLK/FRM 0 4 bit 4 bit
8 bit, CLK/FRM 0 4 bit 4 bit
8 bit, CLK/FRM 2 4 bit 4 bit
8 bit, CLK/FRM 4 8 bit, CLK/FRM 4 8 bit, CLK/FRM 4 8 bit, CLK/FRM 4
8 bit, CLK/FRM 0 4 bit 4 bit
8 bit, CLK/FRM 2 8 bit, CLK/FRM 2 8 bit, CLK/FRM 2 4 bit 4 bit
8 bit, CLK/FRM 0 4 bit 4 bit
16 bit, CLK/FRM 0 4 bit 4 bit 8 bit, CKL/FRM 2
16 bit, CLK/FRM 4 8 bit, CLK/FRM 4 4 bit 16 bit, CLK/FRM 4 8 bit, CLK/FRM 4 8 bit, CLK FRM 6 16 bit, CLK/FRM 4 32 bit, CLK/FRM 0 4 bit
16 bit, CLK/FRM 0 8 bit, CLK/FRM 0 8 bit, CLK/FRM 2
16 bit, CLK/FRM 0 16 bit, CLK/FRM 0
codes are used to initially configure the IDT77V400. These codes are applicable to both the input and output ports, and do not have to be configured the same for both input and output ports.
2. The Data Path Interface (DPI) used by the input and output ports provides the option to combine the four bit data widths together to achieve a higher bandwidth port. The entries in the table are expressed in bus width, and represent the following maximum data rates per port based on ICLK or OCLK frequency: * 4 bit: 155Mbps * 8 bit: 311Mbps * 16 bit: 622Mbps * 32 bit: 1.24Gbps When four bit busses are combined to obtain a higher bandwidth port, the specific CLK and FRM pin to be used for the new wider port is specified. If not specified the CLK and FRM pins match the port number. It is suggested that unused ICLK and IFRM pins be pulled up to Vcc through a resistor, and that unused OCLK and OFRM pins be pulled down to Vss through a resistor. The resistor value is not critical; 5K ohm or less is recommended. 3. This configuration is not supported by the IDT77V500 Switch Controller. Please use the alternate port assignment option immediately prior to this one in the Port Configuration Codes table.
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IDT77V400
Status Register Definition
Register Bit IOD0 IOD1 IOD2 IOD3 IOD4 IOD5 IOD6 IOD7 IOD8 IOD9 IOD10 IOD11 IOD12 IOD13 IOD14 IOD15 IOD16 IOD17 IOD18 IOD19 IOD20 IOD21 IOD22 IOD23 IOD24 IOD25 IOD26 IOD27 IOD28 IOD29 IOD30 IOD31
1.
Error Register Definition
CRC Error4 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- X X X X X X X X
1.
Port 0 0 1 1 2 2 3 3 4 4 5 5 6 6 7 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
ISAM Full1 X -- X -- X -- X -- X -- X -- X -- X -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
ISAM Error2 -- X -- X -- X -- X -- X -- X -- X -- X -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
OSAM Empty3 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- X X X X X X X X -- -- -- -- -- -- -- --
Register Bit IOD0 IOD1 IOD2 IOD3 IOD4 IOD5 IOD6 IOD7 IOD8 IOD9 IOD10 IOD11 IOD12 IOD13 IOD14 IOD15 IOD16 IOD17 IOD18 IOD19 IOD20 IOD21 IOD22 IOD23 IOD2431
Port 0 0 1 1 2 2 0 0 0 0 0 0 1 1 2 2 0 0 0 0 0 0 1 1 2
ISAM Short Cell Error1 X -- -- X -- -- X -- -- X -- -- X -- -- X -- -- X -- -- X -- -- --
ISAM Long ISAM Cell Error1 Overflow1 -- X -- -- X -- -- X -- -- X -- -- X -- -- X -- -- X -- -- X -- -- -- -- X -- -- X -- -- X -- -- X -- -- X -- -- X -- -- X -- -- X --
When the Register Bit is a logic 1(High), the type of error is indicated by an "X".
RAM Address Definition
Used for Store Commands (STEx, STIx) and Load Command (LDOx).
IOD Bit 0-12 13-16 17-26 27-31
1.
Description Cell address in Buffer Memory Switching Memory ID address (in multiple 77V400 device configurations) Unused Edit Buffer Protect/Clear Control Bits1
Logic 1 (HIGH) indicates the ISAM is full.
2. Logic 1 (HIGH) indicates an ISAM error. Error register should be accessed to identify type of error. 3. 4.
Logic 1 (HIGH) indicates the OSAM is empty Logic 1 (HIGH) indicates CRC error on the ISAM.
Updated during STEx and STIx operation.
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IDT77V400
Edit Buffer Protect/Clear Codes
IOD Bit1 31 Mode 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1.
Description 28 Byte 21 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 27 Byte 31 0 1 0 1 0 1 0 1 0 1 1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 1 1 0 1 0 1 No Bytes Selected - No Bytes Cleared Clear Byte 3 Clear Byte 2 Clear Bytes 2 and 3 Clear Byte 1 Clear Bytes 1 and 3 Clear Bytes 1 and 2 Clear Bytes 1, 2 and 3 Clear Byte 0 Clear Bytes 0 and 3 Clear Bytes 0 and 2 Clear Bytes 0, 2 and 3 Clear Bytes 0 and 1 Clear Bytes 0, 1 and 3 Clear Bytes 0, 1 and 2 Clear Bytes 0, 1, 2 and 3 No Bytes Selected - No Protection Done Protect Byte 3 Protect Byte 2 Protect Byte 2 and 3 Protect Byte 1 Protect Bytes 1 and 3 Protect Bytes 1 and 2 Protect Bytes 1, 2 and 3 Protect Byte 0 Protect Bytes 0 and 3 Protect Bytes 0 and 2 Protect Bytes 0, 2 and 3 Protect Bytes 0 and 1 Protect Byes 0, 1 and 3 Protect Byes 0, 1 and 2 Protect Bytes 0, 1, 2 and 3
30 Byte 01 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
29 Byte 11 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1
Byte 0 represents bits 0-7 of the Input Edit Buffer Byte 1 represent bits 8-15 of the Input Edit Buffer Byte 2 represent bits 16-23 of the Input Edit Buffer Byte 3 represent bits 24-31 of the Input Edit Buffer Bit 31 is the MSb of the Input Edit Buffer
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IDT77V400
Cell Alignment Options
Cell Configuration Without HEC SAM Start No Pre/Post Pend Data 1 byte prepended 1 byte postpended 2 bytes prepended 1 byte prepended and 1 byte postpended 2 bytes postpended 3 bytes prepended 2 bytes prepended and 1 byte postpended 1 byte prepended and 2 bytes prepended 3 bytes postpended 4 bytes prepended 3 bytes prepended and 1 byte postpended 2 bytes prepended and 2 bytes postpended 1 byte prepended and 3 bytes postpended 4 bytes postpended
1.
Byte Location in Cell1 With HEC SAM Start 4 3 4 2 3 4 1 2 3 4 -- -- -- -- -- SAM Stop no-skip 0 0 1 0 1 2 0 1 2 3 -- -- -- -- -- SAM Stop skip 1 1 2 1 2 3 1 2 3 -- -- -- -- -- --
SAM Stop 55 55 0 55 0 1 55 0 1 2 55 0 1 2 3
4 3 4 2 3 4 1 2 3 4 0 1 2 3 4
Byte locations are decimal values.
Memory Refresh Requirements
The Buffer Memory of the IDT77V400 must be refreshed by the Control Logic periodically to guarantee data retention. This table defines the maximum refresh interval; that is, the REFRESH command (see "Control Interface Command" Table) must be executed at least 2048 times during each interval. Refresh rate numbers are calculated using a 36MHz SCLK. Refresh is only required for systems which utilize extended cell storage due to queuing requirements above 155Mbps.
Maximum Refresh Interval 32ms 16ms 77V5001 INIT Command Value (Decimal) 9 9 77V5001 INIT Command Value (Hex) 1FF 1FF
Grade Commercial Industrial
1.
This information is provided for applications using the IDT77V500 Switch Controller.
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IDT77V400
77V400 Package Drawing -- 208-pin PQFP
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IDT77V400
77V400 Package Drawing
-- Page Two
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IDT77V400
77V400 Package Drawing -- 256-pin BGA
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IDT77V400
Ordering Information
IDT XXXXX Device Type A Power 999 Speed A Package A Process/ Temperature Range
Blank I
Commercial (0C to +70C) Industrial (-40C to +85C)
DS BC 156
208-pin PQFP (DS208-1) 256 ball BGA (BC256-1)
,
Commercial & Industrial
4-bit Port Bandwidth in Mbps and Parameter Set
S
Standard Power
77V400 Switching Memory
3606 drw sp 19
Datasheet Document History
3/1/99: Pg. 2 Pg. 4 Pg. 5 Pg. 6 Pg. 7 Pg. 8 Updated to new format. Added Industrial Specifications. Added S156 Speed Grade. Updated Description to clarify CRC error operation. Block diagram detail updated for clarity. Figure 2, Edit Buffer Block Diagram corrected to include Output CRC path. Package Diagram notes added for clarification. Pin description table descriptions expanded. IP and OP pin number corrections made. Pin description table descriptions expanded. VTERM in Maximum ratings table reduced to 3.9V. VIH Max reduced to VCC+0.3V. Reset Current parameter removed.
Pg. 14 Pull down resistor values specified in Output Ports section. Pg. 17 Function Sequence Figures modified to remove first IOD identification (state is really unknown). Pg. 19 Modified Port Configuration Code Table to clearly identify the subset supported by IDT77V500. Pg. 20 Improved explanation of Status Register definition and Table; made significant correction and explanation of Error Register definition and Table. Pg. 22 Recommended Refresh specification added. Pg. 23 Updated Ordering Information for S156 speed grade and Industrial temperature product. Pg. 24 Added Preliminary Datasheet definition and Datasheet Document History. 12/11/00: Moved to final. Updated general format and SwitchStar logo. Changed tCYCI, tCHI, tCLI, tHOF, and tCDOD specifications. Added ICLK/SCLK relationship condition, see footnote 1. Corrected Note 2 on Input Port Timing Waveform. Corrected Figure 7, Functional Waveform. Corrected Figure 10, Functional Waveform. Corrected Figures 11 and 12, Functional Waveforms. Added Note 3 to Figure 12. Updated Tech Support phone number. Added BGA Packaging to pages 1, 2, 5, 7, 8, and 23. Deleted S155 speed grade on pages 10, 11, 23. Relaxed tCYCI, tCHI, tCLI specs on page 11. Added Package Drawings for 208 and 256 pin layouts.
1/30/01: 3/31/01:
CORPORATE HEADQUARTERS 2975 Stender Way Santa Clara, CA 95054
for SALES: 800-345-7015 or 408-727-6116 fax: 408-330-1748 www.idt.com
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for Tech Support: switchstarhelp@idt.com phone: 408-492-8208
SwitchStar and the IDT logo are registered trademarks of Integrated Device Technology, Inc.
March 31, 2001


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