Write Operations

BYTE WRITE: A write operation requires an 8-bit data word address following the device address

word and acknowledgment. Upon receipt of this address, the EEPROM 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 EEPROM will output

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

condition. At this time the EEPROM enters an internally timed write cycle, tWR, to the nonvolatile

memory. All inputs are disabled during this write cycle and the EEPROM will not respond until the write is

comp lete (see Figure 5 on page 7).

PAGE WRITE

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

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

microcontroller can transmit up to 31 (64K) more data words. The EEPROM will respond with a "0" after

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

(see Figure 6 on page 7).

The data word address lower five (64K) bits 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 32 (64K) data words are transmitted to the EEPROM,

the data word address will "roll over" and previous data will be overwritten.

ACKNOWLEDGE POLLING: Once the internally timed write cycle has started and the EEPROM inputs

are disabled, acknowled ge polling can be initiated. This involves sending a start condition followed by the

device address word. The read/write bit is representative of the operation desired. Only if the internal write

cycle has completed will the EEPROM respond with a "0", allowing the read or write sequence to continue.

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