R1EX24256ASAS0A Datasheet, PDF (14/23 Pages) Renesas Technology Corp – Two-wire serial interface 256k EEPROM (32-kword × 8-bit)

R1EX24256xxS0A
Write Operations(WP=High)
Byte Write: (Write operation during WP=High status)
A write operation requires an 8-bit device address word with R/W = “0”. Then the EEPROM sends
acknowledgment "0" at the ninth clock cycle. After these, the 32kbit EEPROM receives 2 sequence 8-bit
memory address words.
Upon receipt of this memory address, the EEPROM outputs acknowledgment "0". After receipt of 8-bit
write data, the EEPROM outputs acknowledgment "1"(NO ACK). Then the EEPROM write operations
are not allowed.
Byte Write Operation
WP
Device
address
256k ^{1 0 1 0}
Start
1st Memory
address (n)
W
ACK
R/W
Note: 1. Don't care bit
2nd Memory
address (n)
No ACK
Write data (n)
ACK
ACK
Stop
Page Write:
The page write is the same sequence as the byte write. The page write is initiated by a start condition,
device address word and memory address(n) with every ninth bit acknowledgment"0". But after inputting
write data(Dn) , the EEPROM outputs acknowledgment "1"(NO ACK). Then the EEPROM write
operations are not allowed.
Page Write Operation
WP
256k
Start
Device
address
1010
1st Memory
address (n)
W
ACK
R/W
Note: 1. Don't care bit
2nd Memory
address (n)
No ACK
No ACK
Write data (n) Write data (n+m)
ACK
ACK
Stop
REJ03C0322-0100 Rev.1.00 April. 04, 2008
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