ACE34AC04

4K I

VER 1.1

10

(A)

Byte Write

A byte write operation starts when a micro-controller sends a START bit condition, follows by a

proper EEPROM device address and then a write command. If the device address bits match the

chip select address, the EEPROM device will acknowledge at the 9

th

clock cycle. The

micro-controller will then send the rest of the lower 8 bits word address. At the 18

EEPROM will acknowledge the 8-bit address word. The micro- controller will then transmit the 8 bit

data. Following an ACKNOWLDEGE signal from the EEPROM at the 27

th

clock cycle, the

micro-controller will issue a STOP bit. After receiving the STOP bit, the EEPROM will go into a

self-timed programming mode during which all external inputs will be disabled. After a programming

time of TWC, the byte programming will finish and the EEPROM device will return to the STANDBY

mode.

(B)

Page Write

A page write is similar to a byte write with the exception that one to sixteen bytes can be

programmed along the same page or memory row. All ACE34AC04 are organized to have 16 bytes

per memory row or page.

With the same write command as the byte write, the micro-controller does not issue a STOP bit after

sending the 1st byte data and receiving the ACKNOWLEDGE signal from the EEPROM on the 27th

clock cycle. Instead it sends out a second 8-bit data word, with the EEPROM acknowledging at the

36th cycle.

This data sending and EEPROM acknowledging cycle repeats until the micro-controller

sends a STOP bit after the n × 9

After which the EEPROM device will go into a self-timed partial or full page programming mode. After

the page programming completes after a time of TWC, the devices will return to the STANDBY

mode.

The least significant 4 bits of the word address (column address) increments internally by one after

receiving each data word. The rest of the word address bits (row address) do not change internally,

but pointing to a specific memory row or page to be programmed. The first page write data word can

be of any column address. Up to 16 data words can be loaded into a page. If more then 16 data

words are loaded, the 9

word will be loaded to the 2

(column address) will “roll” over the previously loaded data.

(C)

Acknowledge Polling

ACKNOWLEDGE polling may be used to poll the programming status during a self-timed internal

programming. By issuing a valid read or write address command, the EEPROM will not acknowledge

at the 9th clock cycle if the device is still in the self-timed programming mode. However, if the

programming completes and the chip has returned to the STANDBY mode, the device will return a

valid ACKNOWLEDGE signal at the 9