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Device operation – Rainbow Electronics AT24C16 User Manual

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AT24C01A/02/04/08/16

0180I–SEEPR–10/02

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 AT24C01A/02/04/08/16 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:

1.

Clock up to 9 cycles.

2.

Look for SDA high in each cycle while SCL is high.

3.

Create a start condition.