Rainbow Electronics AT24C1024B - Manual (Page 9)

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AT24C1024B [Preliminary]
5194D–SEEPR–5/07
PAGE WRITE: The 1024K EEPROM is capable of 256-byte page writes.
A page write is initiated the same way 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 255 more data words. The
EEPROM will respond with a zero after each data word received. The microcontroller must ter-
minate the page write sequence with a stop condition (see Figure 9 on page 11).
The data word address lower 8 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 256 data words are
transmitted to the EEPROM, the data word address will “roll over” and previous data will be
overwritten. The address “rollover” during write is from the last byte of the current page to the
first byte of the same page.
ACKNOWLEDGE POLLING: Once the internally timed write cycle has started and the
EEPROM inputs are disabled, acknowledge 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 zero, allowing the read or write sequence to continue.