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 to Figure 1 on page 4). 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 to Figure 2 on page 4).

STOP CONDITION: A low-to-high transition of SDA with SCL hig h is a stop condition. After a read

sequence, the stop command will place the EEPROM in a standby power mode (see Figure 2 on page 4).

ACKNOWLEDGE: All addresses and data words are serially transmitted to and from the EEPROMin

8-bit words. The EEPROM sen ds a "0" to acknowledge that it has received each word. This happens during

the ninth clock cycle.

STANDBY MODE: The LR24C64 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:

1.

Clock up to 9 cycles.

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

3. Create a start cond ition.

Figure 1: Data Validity

Figure 2: Start and Stop Definition

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