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Atmel AT24C04C/08C [DATASHEET]

Atmel-8787D-SEEPROM-AT24C04C,08C-Datasheet_042013

5.

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 (see Figure 5-4 on page 9). 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 5-5 on page 9).

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 5-5 on page 9).

Acknowledge: All addresses and data words are serially transmitted to and from the EEPROM in eight 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 Atmel AT24C04/08C features a low-power standby mode which is enabled:



Upon power-up



After the receipt of the Stop bit and the completion of any internal operations

2-wire Software Reset: After an interruption in protocol, power loss or system reset, any 2-wire part can be reset by

following these steps:

1.

Create a start bit condition

2.

Clock nine cycles

3.

Create another start bit followed by stop bit condition as shown below.

The device is ready for next communication after above steps have been completed.

Figure 5-1. Software Reset

SCL

9

Start

Bit

Start

Bit

Stop

Bit

8

3

2

1

SDA

Dummy Clock Cycles