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KM29W040AT, KM29W040AIT
Document Title
512K x 8 bit NAND Flash Memory
FLASH MEMORY
Revision History
Revision No. History
0.0 1.0 1.1 Initial issue. 1) Changed Operating Voltage 2.7V ~ 5.5V 3.0V ~ 5.5V Data Sheet 1999 1) Added CE don' care mode during the data-loading and reading t
Draft Date
April 10th 1998 July 14th 1998 April 10th 1999
Remark
Preliminary Final Final
The attached datasheets are prepared and approved by SAMSUNG Electronics. SAMSUNG Electronics CO., LTD. reserve the right to change the specifications. SAMSUNG Electronics will evaluate and reply to your requests and questions about device. If you have any questions, please contact the SAMSUNG branch office near you.
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KM29W040AT, KM29W040AIT
512K x 8 Bit NAND Flash Memory
FEATURES
* Voltage Supply: 3.0V~5.5V * Organization - Memory Cell Array : 512K x 8 - Data Register : 32 x 8 bit * Automatic Program and Erase (Typical) - Frame Program : 32 Byte in 500s - Block Erase : 4K Byte in 6ms * 32-Byte Frame Read Operation - Random Access : 15s(Max.) - Serial Frame Access : 120ns(Min.) * Command/Address/Data Multiplexed I/O port * Low Operation Current (Typical) - 10A Standby Current - 10mA Read/ Program/Erase Current * Reliable CMOS Floating-Gate Technology - Endurance : 100K Program/Erase Cycles * 44(40) - Lead TSOP Type II (400mil / 0.8 mm pitch)
FLASH MEMORY
GENERAL DESCRIPTION
The KM29W040A is a 512Kx8bit NAND Flash Memory. Its NAND cell structure provides the most cost-effective solution for Digital Audio Recording. A Program operation programs a 32-byte frame in typically 500s and an Erase operation erase a 4K-byte block in typically 6ms. Data in a frame can be read out at a burst cycle rate of 120ns/byte. The I/O pins serve as the ports for address and data input/output as well as for command inputs. The on-chip write controller automates the program and erase operations, including program or erase pulse repetition where required, and performs internal verification of cell data. The KM29W040A is an optimum solution for flash memory application that do not require the high performance levels or capacity of larger density flash memories. These application include data storage in digital Telephone Answering Devices(TAD) and other consumer applications that require voice data storage.
PIN CONFIGURATION
PIN DESCRIPTION
Pin Name I/O0 ~ I/O7 CLE Pin Function Data Inputs/Outputs Command Latch Enable Address Latch Enable Chip Enable Read Enable Write Enable Write Protect Ground Input Ready/Busy output Power Ground No Connection
VSS CLE ALE WE WP N.C N.C N.C N.C N.C
N.C N.C N.C N.C N.C I/O0 I/O1 I/O2 I/O3 VSS
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23
VCC CE RE R/B GND N.C N.C N.C N.C N.C
ALE CE RE WE WP GND
N.C N.C N.C N.C N.C I/O7 I/O6 I/O5 I/O4 VCC
R/B VCC VSS N.C
44(40) TSOP (II)
NOTE : Connect all VCC and VSS pins of each device to common power supply outputs. Do not leave VCC, VSS or GND inputs disconnected.
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KM29W040AT, KM29W040AIT
Figure 1. FUNCTIONAL BLOCK DIAGRAM
A7 - A18 X-Buffers Latches & Decoders Y-Buffers Latches & Decoders
FLASH MEMORY
4M Bit NAND Flash ARRAY 32Byte x 4frame x 4096row
A0 - A6
Page Register & S/A Command Command Register Y-Gating I/O Buffers & Latches
CE RE WE
Control Logic & High Voltage Generator
I/O0 Global Buffers I/O7
CLE ALE WP
Figure 2. ARRAY ORGANIZATION
Good Block
1Block(32Row) (4K Byte) The 1st Block (4KB) 1 Frame = 32 Byte 1 Row = 4 Frames = 128 Bytes 1 Block = 32 rows = 4K Bytes 1 Device = 32B x 4frames x 32rows x 128blocks = 4Mbits 8 bit 128Byte Column
4M : 4K Row (=128 Blocks)
1
2
3
4
Frame Register 32 Byte
I/O0 ~ I/O7
I/O0 1st Cycle 2nd Cycle 3rd Cycle A0 A8 A16
I/O1 A1 A9 A17
I/O2 A2 A10 A18
I/O3 A3 A11 X*
(1)
I/O4 A4 A12 X*
I/O5 A5 A13 X*
I/O6 A6 A14 *X
I/O7 A7 A15 *X
Column Address (A0-A4) Frame Address (A5-A6) Row Address (A7-A11) Block Address (A12-A18)
NOTE : *(1) : X can be VIL or VIH
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KM29W040AT, KM29W040AIT
PRODUCT INTRODUCTION
FLASH MEMORY
The KM29W040A is a 4M bit memory organized as 4096 rows by 1024 columns. A 256-bit data register is connected to memory cell arrays accommodating data transfer between the registers and the cell array during frame read and frame program operations. The memory array is composed of unit NAND structures in which 8 cells are connected serially. Each of the 8 cells reside in a different row. A block consists of the 32 rows, totaling 4096 unit NAND structures of 8bits each. The array organization is shown in Figure 2. The program and read operations are executed on a frame basis, while the erase operation is executed on a block basis. The memory array consists of 128 separately erasable 4K-byte blocks. The KM29W040A has addresses multiplexed into 8 I/O pins. This scheme not only reduces pin count but allows systems upgrades to higher density flash memories by maintaining consistency in system board design. Command, address and data are all written through I/Os by bringing WE to low while CE is low. Data is latched on the rising edge of WE. Command Latch Enable(CLE) and Address Latch Enable(ALE) are used to multiplex command and address respectively, via the I/O pins. All commands require one bus cycle except for Block Erase command which requires two cycles. For byte-level addressing, the 512K byte physical space requires a 19-bit address, low row address and high row address. Frame Read and frame Program require the same three address cycles following by a command input. In the Block Erase operation, however, only the two row address cycles are required. Device operations are selected by writing specific commands into the command register. Table 1 defines the specific commands of the KM29W040A.
Table 1. COMMAND SETS
Function Read Reset Frame Program Block Erase Status read Read ID 1st. Cycle 00h FFh 80h 60h 70h 90h 2nd. Cycle 10h D0h O O Acceptable Command during Busy
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KM29W040AT, KM29W040AIT
PIN DESCRIPTION
Command Latch Enable(CLE)
FLASH MEMORY
The CLE input controls the path activation for commands sent to the command register. When active high, commands are latched into the command register through the I/O ports on the rising edge of the WE signal.
Address Latch Enable(ALE)
The ALE input controls the path activation for address and input data to the internal address/data register. Addresses are latched on the rising edge of WE with ALE high, and input data is latched when ALE is low.
Chip Enable(CE)
The CE input is the device selection control. When CE goes high during a read operation the device is returned to standby mode. However, when the device is in the busy state during program or erase, CE high is ignored, and does not return the device to standby mode.
Write Enable(WE)
The WE input controls writes to the I/O port. Commands, address and data are latched on the rising edge of the WE pulse.
Read Enable(RE)
The RE input is the serial data-out control, and when active drives the data onto the I/O bus. Data is valid tREA after the falling edge of RE which also increments the internal column address counter by one.
I/O Port : I/O0 ~ I/O7
The I/O pins are used to input command, address and data, and to output data during read operations. The I/O pins float to high-z when the chip is deselected or when the outputs are disabled.
Write Protect(WP)
The WP pin provides inadvertent write/erase protection during power transitions. The internal high voltage generator is reset when the WP pin is active low.
Ready/Busy(R/B)
The R/B output indicates the status of the device operation. When low, it indicates that a program, erase or random read operation is in process and returns to high state upon completion. It is an open drain output and does not float to high-z condition when the chip is deselected or when outputs are disabled.
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KM29W040AT, KM29W040AIT
ABSOLUTE MAXIMUM RATINGS
Parameter Voltage on any pin relative to VSS Temperature Under Bias Storage Temperature Short Circuit Output Current KM29W040AT KM29W040AIT TSTG IOS Symbol VIN TBIAS Rating -0.6 to +7.0 -10 to +125 -40 to +125 -65 to +150 5
FLASH MEMORY
Unit V C C mA
NOTE : 1. Minimum DC voltage is -0.3V on input/output pins. During transitions, this level may undershoot to -2.0V for periods <20ns. Maximum DC voltage on input/output pins is VCC+0.3V which, during transitions, may overshoot to VCC+2.0V for periods <20ns. 2. Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded. Functional operation should be restricted to the conditions as detailed in the operational sections of this data sheet. Exposure to absolute maximum rating conditions for extended periods may affect reliability.
RECOMMENDED OPERATING CONDITIONS
(Voltage reference to GND, KM29W040AT:TA=0 to 70C, KM29W040AIT:TA=-40 to 85C)
Parameter Supply Voltage Supply Voltage Symbol VCC VSS Min 3.0 0 Typ. 0 Max 5.5 0 Unit V V
DC AND OPERATING CHARACTERISTICS(Recommended operating conditions otherwise noted.)
Parameter Burst Read Cycle Operating Current Program Erase Symbol ICC1 ICC2 ICC3 ISB1 ISB2 ILI ILO VIH VIL VOH VOL IOL(R/B) IOH=-400A IOL=2.1mA VOL=0.4V Test Conditions tcycle=120ns,CE=VIL, IOUT=0mA CE=VIH, WP=0V/VCC CE=VCC-0.2, WP=0V/VCC VIN=0 to 5.5V VOUT=0 to 5.5V Vcc = 3.0V ~ 3.6V Min 2.4 -0.3 2.4 8 Typ 5 5 5 10 10 Max 10 10 10 1 50 10 10 VCC+ 0.3 0.6 0.4 Vcc = 3.6V ~ 5.5V Min 2.4 -0.3 2.4 8 Typ 10 10 10 10 10 Max 20 20 20 1 50 10 10 VCC+ 0.5 0.8 0.4 mA V A mA Unit
Stand-by Current(TTL) Stand-by Current(CMOS) Input Leakage Current Output Leakage Current Input High Voltage, All inputs Input Low Voltage, All inputs Output High Voltage Level Output Low Voltage Level Output Low Current(R/B)
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KM29W040AT, KM29W040AIT
VALID BLOCK
Parameter Valid Block Number Symbol NVB Min 125 Typ. -
FLASH MEMORY
Max 128 Unit Block
NOTE : 1. The KM29W040A may include invalid blocks. Invalid blocks are defined as blocks that contain one or more bad bits. Do not try to access these invalid blocks for program and erase. During its lifetime of 10 years and/or 100K program/erase cycles,the minimum number of valid blocks are guaranteed though its initial number could be reduced. (Refer to the attached technical notes) 2. The 1st block, which is placed on 00h block address, is guaranteed to be a valid block
AC TEST CONDITION
(KM29W040AT:TA=0 to 70C, KM29W040AIT:TA=-40 to 85C, VCC=3.0V ~ 5.5V unless otherwise noted) Parameter Input Pulse Levels Input Rise and Fall Times Input and Output Timing Levels Output Load Value Vcc=3.0V ~ 3.6V 0.4V to 2.6V 5ns 0.8V and 2.0V 1 TTL GATE and CL = 100pF Vcc=3.6V ~ 5.5V 0.4V to 2.6V
CAPACITANCE(TA=25C, Vcc=5.0V, f=1.0MHz)
Item Input / Output Capacitance Input Capacitance Symbol CI/O CIN Test Condition VIL=0V VIN=0V Min Max 10 10 Unit pF pF
NOTE : Capacitance is periodically sampled and not 100% tested.
MODE SELECTION
CLE H L H L L L L X X X X ALE L H L H L L L X X X(1) X CE L L L L L L L X X X H H H X X X X H X X X X WE RE H H H H H WP X X H H H X X H H L 0V/VCC
(2)
Mode Read Mode Command Input Address Input(3clock) Command Input Address Input(3clock)
Write Mode Data Input
Sequential Read & Data Output During Read(Busy) During Program(Busy) During Erase(Busy) Write Protect Stand-by
NOTE : 1. X can be VIL or VIH 2. WP should be biased to CMOS high or CMOS low for standby.
Program/Erase Characteristics
Parameter Program Time Number of Partial Program Cycles in the Same Frame Block Erase Time Symbol tPROG Nop tBERS Min Typ 0.5 6 Max 1 10 10 Unit ms cycles ms
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KM29W040AT, KM29W040AIT
AC Timing Characteristics for Command / Address / Data Input
Parameter CLE Set-up Time CLE Hold Time CE Setup Time CE Hold Time WE Pulse Width ALE Setup Time ALE Hold Time Data Set-up Time Data Hold Time Write Cycle Time WE High Hold Time Symbol tCLS tCLH tCS tCH tWP tALS tALH tDS tDH tWC tWH Min 50 50 50 50 60 50 50 40 20 120 40
FLASH MEMORY
Max Unit ns ns ns ns ns ns ns ns ns ns ns
AC Characteristics for Operation
Parameter Data Transfer from Cell to Register ALE to RE Delay CE low to RE low (ID read) Ready to RE Low RE Pulse Width WE High to Busy Read Cycle Time RE Access Time RE High to Output Hi-Z CE High to Output Hi-Z RE High Hold Time Output Hi-Z to RE Low CE High to Ready(in case of interception by CE at read) RE Low to Status Output CE Low to Status Output WE High to RE Low RE access time(Read ID) Device Resetting Time(Read/Program/Erase)
(1)
Symbol tR tAR tCR tRR tRP tWB tRC tREA tRHZ tCHZ tREH tIR tCRY tRSTO tCSTO tWHR tWHRID tRST
Min 250 250 100 60 120 0 40 0 50 100 -
Max 15 200 50 30 50 100+tr(R/B) 60 70 5/10/500
(2)
Unit s ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns s
NOTE : 1. If CE goes high within 50ns after the third address input, R/B will not return to VOL. 2. The time to Ready depends on the value of the pull-up resistor tied R/B pin.
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KM29W040AT, KM29W040AIT
NAND Flash Technical Notes
Invalid Block(s)
FLASH MEMORY
Invalid blocks are defined as blocks that contain one or more invalid bits whose reliability is not guaranteed by Samsung. Typically, an invalid block will contain a single bad bit. The information regarding the invalid block(s) is so called as the invalid block information. The invalid block information is written to the 1st or the 2nd page of the invalid block(s) with 00h data. Devices with invalid block(s) have the same quality level or as devices with all valid blocks and have the same AC and DC characteristics. An invalid block(s) does not affect the performance of valid block(s) because it is isolated from the bit line and the common source line by a select transistor. The system design must be able to mask out the invalid block(s) via address mapping. The 1st block of the NAND Flash, however, is fully guaranteed to be a valid block.
Identifying Invalid Block(s)
All device locations are erased(FFh) except locations where the invalid block information is written prior to shipping. Since the
invalid block information is also erasable in most cases, it is impossible to recover the information once it has been erased. Therefore, the system must be able to recognize the invalid block(s) based on the original invalid block information and create the invalid block table via the following suggested flow chart(Figure 1). Any intentional erasure of the original invalid block information is prohibited.
Start
Set Block Address = 0
Increment Block Address
Create (or update) Invalid Block(s) Table
No
Check "FFH" ?
*
Check "FFH" on the 1st and 2nd page
Yes No
Last Block ?
Yes
End
Figure 1. Flow chart to create invalid block table.
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KM29W040AT, KM29W040AIT
KM29W040A Technical Notes(Continued)
Error in program or erase operation
FLASH MEMORY
The device may fail during a program or erase operation. The following possible failure modes should be considered when implementing a highly reliable system. Failure Mode Block Frame Single Bit Erase Failure Program Failure Program Failure ("1" --> "0") Detection and Countermeasure sequence Read after Erase --> Block Replacement Status Read after Program --> Block Replacement Block Verify after Program --> Block Replacement
Block Replacement
During Program operation ;
Buffer memory
error occurs
Block A
When the error happens in Block "A", try to reprogram the data into another Block "B" by reloading from an external buffer. Then, prevent further system access to Block "A"(by creating a "bad block" table or other appropriate scheme.)
Block B
During Erase operation ;
When the error occurs after an erase operation, prevent future accesses to this bad block (again by creating a table within the system or other appropriate scheme.)
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KM29W040AT, KM29W040AIT
System Interface Using CE don' -care. t
FLASH MEMORY
For a easier system interface, CE may be inactive during the data-loading or sequential data-reading as shown below. The internal 32byte page registers are utilized as seperate buffers for this operation and the system design gets more flexible. In addition, for voice or audio applications which use slow cycle time on the order of u-seconds, de-activating CE during the data-loading and reading would provide significant savings in power consumption.
Figure 3. Program Operation with CE don' -care. t CLE
CE don'-care t
CE
WE ALE
I/O0~7
80H
Start Add.(3Cycle)
Data Input
Data Input
10H
tCS CE
(Max. 60ns)
tCH CE
tCEA
tREA tWP WE I/O0~7 out RE
Timing requirements : If CE is is exerted high during sequential data-reading, the falling edge of CE to valid data(tCEA) must be kept greater than 60ns.
Figure 4. Read Operation with CE don' -care. t
CLE
CE don'-care t
CE
RE ALE R/B tR
WE
I/O0~7
00H
Start Add.(3Cycle)
Data Output(sequential)
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KM29W040AT, KM29W040AIT
* Command Latch Cycle
FLASH MEMORY
CLE tCLS tCS CE tCLH tCH
tWP WE
tALS ALE tDS I/O0~7
tALH
tDH
Command
* Address Latch Cycle
tCLS CLE
tCS CE
tWC
tWC
tWP WE tWH tALS ALE tDS I/O0~7 tDH
tWP tWH
tWP
tALH
tDS
tDH
tDS
tDH
A0~A7
A8~A15
A16~A18
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KM29W040AT, KM29W040AIT
* Input Data Latch Cycle
FLASH MEMORY
tCLH CLE
tCH CE
tALS ALE
tWC
tWP WE tDS I/O0~7 tWH tDH
tWP
tDH
tWP tDH
tDS
tDS
DIN 0
DIN 1
DIN 31
* Burst Read Cycle After Frame Access(CLE=L, WE=H, ALE=L)
CE
tRC tRHZ* tRP tREA tREH
RE tRHZ tRHZ*
I/O0~7 tRR R/B
Dout
Dout
tREA
tREA
Dout
NOTES : Transition is measured200mV from steady state voltage with load. This parameter is sampled and not 100% tested.
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KM29W040AT, KM29W040AIT
* Status Read Cycle
tCLS CLE tCLH tREA CE tCH tWP WE tWHR RE tDS I/O0~7 70H tDH tIR tRSTO tCSTO
FLASH MEMORY
tCHZ
tRHZ
Status Output
READ OPERATION(READ ONE FRAME)
CLE
CE
WE tWB tAR ALE tR RE tRR I/O0~7
00h
tCHZ
tRC
tRHZ
A0 ~ A7
A8 ~ A15
A16 ~ A18
Dout N
Dout N+1 Dout N+2 Dout N+3 Dout 32
Column Address
Row Address Busy
R/B
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KM29W040AT, KM29W040AIT
READ OPERATION(INTERCEPTED BY CE)
FLASH MEMORY
CLE
CE
WE tWB tAR ALE tR RE tRR I/O0~7
00h
tCHZ
A0~A7
A8~A15
A16~A18
Dout N
Dout N+1
Dout N+2
Dout N+3
Column Address
Row Address Busy
R/B
PROGRAM OPERATION
CLE
CE tWC WE tWB ALE tPROG tWC tWC
RE
Din Din N N+1 1 up to 32 Byte Data Serial Input Din 31
I/O0~7
80H
A0 ~ A7 A8 ~ A15 A16 ~ A18 Row Address
10H Program Command
70H Read Status Command
I/O0
Sequential Data Column Input Command Address
15
R/B
I/O0=0 Successful Program I/O0=1 Error in Program
KM29W040AT, KM29W040AIT
BLOCK ERASE OPERATION
FLASH MEMORY
CLE
CE
WE tWB ALE tBERS
RE
I/O0~7
60H
A8~A15
A16~A18
DOH
Block Address
Auto Block Erase Setup Command
Erase Command
16
R/B
Busy
KM29W040AT, KM29W040AIT
DEVICE OPERATION
FRAME READ
FLASH MEMORY
Upon initial device power up or after excution of Reset(FFh) command, the device defaults to Read mode. This operation is also initiated by writing 00H to the command register along with three address cycles. The three cycle address input must be given for access to each new frame. The read mode is enabled when the frame address is changed. 32 bytes of data within the selected frame are transferred to the data registers in less than 15s(tR). The CPU can detect the completion of this data transfer(tR) by analyzing the output of R/B pin. Once the data in a frame is loaded into the registers, they may be read out in 120ns cycle time by sequentially pulsing RE with CE staying low. High to low transitions of the RE clock output the data starting from the selected column address up to the last column address within the frame(column 32).
Figure 3. Read Operation
CLE CE WE ALE RE R/B I/O0~7
00H
Busy(Seek Time)
Start Add.(3Cycle) A0~A7 & A8~A18
Data Output(Sequential)
Seek Time
0
31
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KM29W040AT, KM29W040AIT
FRAME PROGRAM
FLASH MEMORY
The device is programmed on a frame basis. The addressing may be done in random order in a block. A frame program cycle consist of a serial data loading period in which up to 32 bytes of data must be loaded into the device, and a nonvolatile programming period in which the loaded data is programmed into the appropriate cells. The sequential data loading period begins by inputting the frame program setup command(80H), followed by the three cycle address input and then sequential data loading. The bytes other than those to be programmed do not need to be loaded. The frame Program confirm command(10H) initiates the programming process. Writing 10H alone without previously entering the serial data will not initiate the programming process. The internal write controller automatically executes the algorithms and timings necessary for program and verify, thereby freeing the CPU for other tasks. The CPU can detect the completion of a program cycle by monitoring the R/B output, or the Status bit(I/O6) of the Status Register. Only the Read Status command and Reset command are valid while programming is in progress. When the frame Program is complete, the Write Status Bit(I/O0) may be checked. The internal write verify detects only errors for "1"s that are not successfully programmed to "0"s. The command register remains in Read Status command mode until another valid command is written to the command register.
Figure 4. Frame Program Operation tPROG R/B I/O0~7
80H
Address & Data Input A0~A7 & A8~A18 32 Byte Data
10H
FRAME PROGRAM
While the frame size of the device is 32 Bytes, not all the bytes in a frame have to be programmed at once. The device supports partial frame programming in which a frame may be partially programmed up to 10 separate program operations. The program size in each of the 10 partial program operations is freely determined by the user and do not have to be equal to each other or to any preset size. However, the user should ensure that the partial program units within a frame do not overlap as "0" data cannot be changed to "1" data without an erase operation. To perform a partial frame program operation, the user only writes the partial frame data that is to programmed. Just as in the standard frame program operation, an 80H command is followed by start address data. However, only the partial program data need be divided when programming a frame in 10 partial program operations.
Figure 5. Example of Dividing a Frame into 10 Partial Program Units
1st partial program start address (00h) 2nd partial program start address (04h) 3rd partial program start address (06h) : : : : : : 9th partial program start address (18h) 10th partial program start address (1Fh) FA A2 43 CB 81 28 E0 2A D5 - - - - - - 32 B5 7D 6F AA E1 D7 C0 Single Frame
10th partial frame program data 9th partial frame program data : : : : : : 3rd partial frame program data 2nd partial frame program data 1st partial frame program data
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KM29W040AT, KM29W040AIT
BLOCK ERASE
FLASH MEMORY
The Erase operation is done 4K Bytes(1 block) at a time. Block address loading is accomplished in two cycles initiated by an Erase Setup command(60H). Only address A12 to A18 are valid while A8 to A11 is ignored. The Erase Confirm command(D0H) following the block address loading initiates the internal erasing process. This two-step sequence of setup followed by execution command ensures that memory contents are not accidentally erased due to external noise conditions. At the rising edge of WE after the erase confirm command input, the internal write controller handles erase, erase-verify and pulse repetition where required.
Figure 6. Block Erase Operation tBERS R/B I/O0~7
60H
Address Input(2Cycle) Block Add. : A8~A18
D0H
READ STATUS
The device contains a Status Register which may be read to find out whether program or erase operation is complete, and whether the program or erase operation completed successfully. After writing 70H command to the command register, a read cycle outputs the contents of the Status Register to the I/O pins on the falling edge of CE or RE, whichever occurs last. This two line control allows the system to poll the progress of each device in multiple memory connections even when R/B pins are common-wired. RE or CE does not need to be toggled for updated status. Refer to table 2 for specific Status Register definitions. The command register remains in Status Read mode until further commands are issued to it. Therefore, if the status register is read during a random read cycle, the required read command(00H) should be input before serial page read cycle.
Table2. Status Register Definition
SR I/O0 I/O1 I/O2 I/O3 I/O4 I/O5 I/O6 I/O7 Device Operation Write Protect Reserved for Future Use Status Program Definition "0" : Successful Program "1" : Error in Program "0" "0" "0" "0" "0" "0" "0" : Busy "0" : Protected "1" : Ready "1" : Not Protected
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KM29W040AT, KM29W040AIT
RESET
FLASH MEMORY
The device offers a reset feature, executed by writing FFH to the command register. When the device is in Busy state during the read, program or erase mode, the reset operation will abort these operation. In the case of Reset during Program or Erase operations, the contents of memory cells being altered are no longer valid, as the data will be partially programmed or erased. The device enters the Read mode after completion of Reset operation as shown Table 3. If the device is already in reset state a new reset command will not be accepted to by the command register. The R/B pin transitions to low for tRST after the Reset command is written. Reset command is not necessarily for normal device operation. Refer to Figure 7 below.
Figure 7. RESET Operation tRST
R/B I/O0~7
FFH
Table3. Device Status
After Power-up Operation Mode Read After Reset Read
READY/BUSY
The device has a R/B output that provides a hardware method of indicating the completion of a frame program, erase or read seek completion. The R/B pin is normally high but transitions to low after program or erase command is written to the command register or a random read is begin after address loading. It returns to high when the internal controller has finished the operation. The pin is an open-drain driver thereby allowing two or more R/B outputs to be Or-tied. An appropriate pull-up resister is required for proper operation and the value may be calculated by following equation.
VCC VCC(Max.) - VOL(Max.) Rp = R/B open drain output where IL is the sum of the input currents of all devices tied to the R/B pin. IOL + IL = Note* 8mA + IL
GND Device
Note* KM29W040A ; 5.1V when Vcc=3.6V~5.5V 3.2V when Vcc=3.0V~3.6V
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KM29W040AT, KM29W040AIT
DATA PROTECTTION
FLASH MEMORY
The device is designed to offer protection from any involuntary program/erase during power-transitions. An internal voltage detector disables all functions whenever Vcc is below about 2V. WP pin provides hardware protection and is recommended to be kept at VIL during power-up and power-down as shown in Figure 8. The two step command sequence for program/erase provides additional software protection.
Figure 8. AC Waveforms for Power Transition
~ 2.5V
~ 2.5V
VCC
WP
READ ID
The device contains a product identification mode, initiated by writing 90H to the command register, followed by an address input of 00H. Two read cycles sequentially output the manufacture code(ECH), and the device code (A4H). The command register remains in Read ID mode until further commands are issued to it. Figure 9 shows the operation sequence.
Figure 9. Read ID Operation
CLE tCR CE tWHRID WE ALE RE I/O0~7 tREA
90H Add. Input(1Cycle) A0~A7:"0" Dout(ECH) Maker code Dout(A4H) Device code
tAR
21
High
KM29W040AT, KM29W040AIT
PACKAGE DIMENSIONS
44(40) LEAD PLASTIC THIN SMALL OUT-LINE PACKAGE TYPE(II) 44(40) - TSOP2 - 400F
FLASH MEMORY
Unit :mm/Inch
0~8 0.25 0.010 TYP #44(40) #23(21) 0.45~0.75 0.018~0.030 11.760.20 0.4630.008 10.16 0.400 0.50 0.020 #1 #22(20)
+0.10
0.15 -0.05 0.006 -0.002
+0.004
18.410.10 0.7250.004
1.000.10 0.0390.004
1.20 Max. 0.047
18.81 Max. 0.741
0.10 MAX 0.004 0.05 Min. 0.002
(
0.805 ) 0.032
0.350.10 0.0140.004
0.80 0.0315
22

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