Read Operations

Read operations are initiated the same way as write operations with the exception that the read/write select

bit in the device address word is set to "1". There are three read operations: current address read, random

address read and sequential read.

CURRENT ADDRESS READ:

The

internal data word address counter

maintains the last accessed

address, and incremented by one.This address stays valid between operations as long as the chip power is

maintained. The address

"roll over" during read is from the last byte of the last memory page to the first

byte of the first page.The address "roll over" during write is from the last byte of the current page to the

first byte of the same page.

Once the device address with the read/write select bit set to "1" is clocked in and acknowledged by the

EEPROM, the current address data word is serially clocked out. The microcontroller does not respond with

an input "0" but does generate a following stop condition (see Figure 7 on page 8).

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 acknowled ge, 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 9 on page 8).

Figure 4: Device Address

Figure 5: Byte Write

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