A24C64
MEMORY EEPROM
AiT Semiconductor Inc.
www.ait-ic.com
64k BITS (8192 X 8) TWO-WIRE SERIAL
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 “0” but does
generate a following stop condition (see Figure 10 on page13).
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 “0” but does generate a following stop condition (see Figure 11 on page13)
READ IDENTIFICATION PAGE: The Identification Page (32 bytes) is an additional page which can be written
and (Iater) permanently locked in Read-only mode.
The Identification Page can be read by issuing an Read Identification Page instruction. This instruction uses
the same protocol and format as the Random Address Read (from memory array) with device type identifier
defined as 1011b. The MSB address bits B15/B6 are don't care, the LSB address bits B5/B0 define the byte
address inside the Identification Page. The number of bytes to read in the ID page must not exceed the page
boundary (e.g.: when reading the Identification Page from location 10d, the number of bytes should be less
than or equal to 22, as the ID page boundary is 32 bytes)
LOCK IDENTIFUCATION PAGE: The Lock Identification Page instruction (Lock ID) permanently locks the
Identification page in Read-only mode. The Lock ID instruction is similar to Byte Write (into memory array)
with the following specific conditions:
Device type identifier = 1011b
Address bit B10 must be '1'; all other address bits are don't care
The data byte must be equal to the binary value xxxx xx1x, where x is don't care
REV2.0
- SEP 2008 RELEASED, NOV 2016 UPDATED -
- 10 -
AITSEMI [ AiT Semiconductor ]
