at34c02b ATMEL Corporation, at34c02b Datasheet - Page 6

• Manufacturer Part Number: at34c02b
• Description: Two-wire Serial Eeprom With Permanent And Reversible Software Write Protect 2k 256 X 8
• Manufacturer: ATMEL Corporation

Memory Organization
Device Operation
6
AT34C02B
AT34C02B, 2K Serial EEPROM: The 2K is internally organized with 16 pages of 16
bytes each. Random word addressing requires a 8-bit data word address.
CLOCK and DATA TRANSITIONS: The SDA pin is normally pulled high with an exter-
nal device. Data on the SDA pin may change only during SCL low time periods (see
Figure 4 on page 7). Data changes during SCL high periods will indicate a start or stop
condition as defined below.
START CONDITION: A high-to-low transition of SDA with SCL high is a start condition
which must precede any other command (see Figure 5 on page 8).
STOP CONDITION: A low-to-high transition of SDA with SCL high is a stop condition.
After a read sequence, the stop command will place the EEPROM in a standby power
mode (see Figure 5 on page 8).
ACKNOWLEDGE: All addresses and data words are serially transmitted to and from
the EEPROM in 8-bit words. The EEPROM sends a zero to acknowledge that it has
received each word. This happens during the ninth clock cycle.
STANDBY MODE: The AT34C02B features a low-power standby mode which is
enabled: (a) upon power-up or (b) after the receipt of the STOP bit and the completion of
any internal operations.
MEMORY RESET: After an interruption in protocol, power loss or system reset, any
Two-wire part can be reset by following these steps:
(a) Clock up to 9 cycles, (b) look for SDA high in each cycle while SCL is high and then
(c) create a start condition.
3417E–SEEPR–1/07