Rainbow Electronics AT24C16A - Manual (Page 6)

6
AT24C02A/04A/08A/16A
0976D–12/01
Device Operation
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 (refer to
Data Validity 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 (refer to Start and Stop Definition timing
diagram).
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 (refer to Start and Stop Definition timing diagram).
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 AT24C02A/04A/08A/16A 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 2-
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.