AT24C32A_14 Datasheet, PDF (6/18 Pages) ATMEL Corporation – Schmitt Trigger, Filtered Inputs for Noise Suppression

Device
Operation
CLOCK and DATA TRANSITIONS: The SDA pin is normally pulled high with an external
device. Data on the SDA pin may change only during SCL low time periods (refer to Data Valid-
ity timing diagram). 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 Fig-
ure 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 during the ninth clock cycle to acknowl-
edge that it has received each word.
STANDBY MODE: The AT24C32A/64A features a low power standby mode which is enabled:
a) upon power-up and 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 as SDA is high.
6 AT24C32A/64A
5120D–SEEPR–6/08