ACE24C02A

Two-wire Serial EEPROM

VER 1.2

9

Random Read:

A random read requires a “dummy” byte write sequence to load in the data word address. Once the

device address word and data word address are clocked in and acknowledged by the EEPROM, the

microcontroller must generate another start condition. The microcontroller now initiates a current

address read by sending a device address with the read/write select bit high. The EEPROM

acknowledges the device address and serially clocks out the data word. The microcontroller does not

respond with a zero but does generate a following stop condition (refer to Figure 11).

Sequential Read:

Sequential reads are initiated by either a current address read or a random address read. After the

microcontroller receives a data word, it responds with an acknowledge. As long as the EEPROM

receives an acknowledge, it will continue to increment the data word address and serially clock out

sequential data words. When the memory address limit is reached, the data word address will “roll

over” and the sequential read will continue. The sequential read operation is terminated when the

microcontroller does not respond with a zero but does generate a following stop condition (refer to

Figure 12).

Figure 7．Device Address

Figure 8．Byte Write

Figure 9．Page Write

MSB

LSB

1

0

1

0

x

x

x

R/W