ACE24C256C

Two-wire serial EEPROM

VER 1.2

9

Instructions

Write Operations

(A)

Byte Write

A write operation requires two 8-bit data word address (A14/A0) following the device address word and

acknowledgment. Upon receipt of this address, the ACE24C256C

will again respond with a “0” and then

clock in the first 8-bit data word. Following receipt of the 8-bit data word, the ACE24C256C will output a

“0” and the addressing device, such as a microcontroller, must terminate the write sequence with a stop

condition. And then the ACE24C256C enters an internally timed write cycle, all inputs are disabled during

this write cycle and the ACE24C256C will not respond until the write is complete (see Figure 8).

Notes:

x means don’t care.

(B)

Page Write

A page write is initiated the same as a byte write, but the master does not send a stop condition after

the first data word is clocked in. Instead, after the ACE24C256C acknowledges receipt of the first

data word, the master can transmit more data words. The ACE24C256C

will respond with a “0” after

each data word received. The microcontroller must terminate the page write sequence with a stop

condition.

The lower six bits of the data word address are internally incremented following the receipt of each data

word. The higher data word address bits are not incremented, retaining the memory page row location.

When the word address, internally generated, reaches the page boundary, the following byte is placed at

the beginning of the same page. If more than 64 data words are transmitted to the ACE24C256C, the data

word address will roll-over, and previous data will be overwritten. The address roll-over during write is

from the last byte of the current page to the first byte of the same page.

Figure8：Byte Write

Figure9：Page Write