ACE24AC16COMTH datasheet(6/20 Pages) ACE

6 / 20 page

ACE24AC16C

Two-wire Serial EEPROM

VER 1.1

Device Addressing

The 2-wire serial bus protocol mandates an 8 bits device address word after a START bit condition to

invoke valid read or write command. The first four most significant bits of the device address must be

1010, which is common to all serial EEPROM devices. The next bit is device address bit. This device

address bit (5th) is to match with the external chip select/address pin states. If a match is made, the

EEPROM device outputs an ACKNOWLEDGE signal after the 8th read/write bit, otherwise the chip will go

into STANDBY mode. The last or 8th bit is a read/write command bit. If the 8th bit is at VIH then the chip

goes into read mode. If a “0” is detected, the device enters programming mode. ACE24AC16C does not

use any device address bit. Only one ACE24AC16C device can be used on the on 2-wire bus.

Write Operations

(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 9th clock cycle. The

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

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

data. Following an ACKNOWLDEGE signal from the EEPROM at the 27th 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 ACE24AC16C 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 × 9th clock cycle. 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.

ACE24AC16COMTH Datasheet(PDF) 6 Page - ACE Technology Co., LTD.