PRELIMINARY INFORMATION
June 2000
FM34W02
2K-Bit Standard 2-Wire Bus Interface Serial EEPROM
with Full Array Write Protect
Designed with Permanent Write-Protection for First 128 Bytes for Serial Presence
Detect Application on Memory Modules (PC100/PC133 Compliant)
General Description
Features
The FM34W02 is 2048 bits of CMOS non-volatile electrically
erasable memory. This device is specifically designed to support
Serial Presence Detect circuitry in memory modules. This com-
munications protocol uses CLOCK (SCL) and DATA I/O (SDA)
lines to synchronously clock data between the master (for ex-
ample a microprocessor) and the slave EEPROM device(s).
I PC100/PC133 Compliant
I Extended Operating Voltage: 2.7V-5.5V
I Software Write-Protection for first 128 bytes
I Hardware Write-Protection for entire memory array
I 200 µA active current typical
The contents of the non-volatile memory allows the CPU to
determine the capacity of the module and the electrical character-
istics of the memory devices it contains. This will enable "plug and
play" capability as the module is read and PC main memory
resources utilized through the memory controller.
– 1.0 µA standby current typical (L)
– 0.1 µA standby current typical (LZ)
I IIC compatible interface
– Provides bidirectional data transfer protocol
I Sixteen byte page write mode
– Minimizes total write time per byte
The first 128 bytes of the memory of the FM34W02 can be
permanentlyWriteProtectedbywritingtothe"WRITEPROTECT"
Register. Write Protect implementation details are described
underthesectiontitledAddressingtheWPRegister. Inaddition,
like the NM24Wxx product family, the entire memory array can be
write-protected through "WP" pin.
I Self timed write cycle
- Typical write cycle time of 6ms
I Endurance: 1,000,000 data changes
I Data retention greater than 40 years
TheFM34W02isavailableinaJEDECstandardTSSOPpackage
for low profile memory modules for systems requiring efficient
spaceutilizationsuchasinanotebookcomputer. Twooptionsare
available: L - Low Voltage and LZ - Low Power, allowing the part
to be used in systems where battery life is of primary importance.
I Packages available: 8-pin TSSOP and 8-pin SO
I Temperature Ranges: Commercial and Extended
Block Diagram
V
CC
V
SS
WP
H.V. GENERATION
TIMING &CONTROL
START CYCLE
START
STOP
SDA
LOGIC
CONTROL
LOGIC
SLAVE ADDRESS
REGISTER &
COMPARATOR
2
E
PROM
16
ARRAY
16 x 16 x 8
XDEC
SCL
LOAD
INC
A2
A1
A0
WORD
ADDRESS
COUNTER
0/1/2/3
4
16
4
R/W
YDEC
Device Address Bits
8
Write Protect
Register
CK
D
OUT
DATA REGISTER
D
IN
DS800041-1
1
© 2000 Fairchild Semiconductor International
FM34W02 Rev. A
www.fairchildsemi.com