R1EX24128BSAS0I Datasheet, PDF (13/18 Pages) Renesas Technology Corp – Two-wire serial interface 128k EEPROM (16-kword × 8-bit)

R1EX24128BSAS0I/R1EX24128BTAS0I
Random Read:
This is a read operation with defined read address. A random read requires a dummy write to set read address. The
EEPROM receives a start condition, device address word (R/W=0) and memory address 2 × 8-bit sequentially. The
EEPROM outputs acknowledgment “0” after receiving memory address then enters a current address read with
receiving a start condition. The EEPROM outputs the read data of the address which was defined in the dummy write
operation. After receiving acknowledgment “1”(no acknowledgment) and a following stop condition, the EEPROM
stops the random read operation and returns to a standby state.
Random Read Operation
128k
Start
Device
address
@@@
1010
W
1st Memory
address (n)
ACK
R/W
Dummy write
2nd Memory
address (n)
ACK
Device
address
###
1010
R
Start ^R/W
ACK
ACK
Read data (n)
No ACK
Stop
Current address read
Notes: 1. Don't care bit
2. 2nd device address code (#) should be same as 1st (@).
Sequential Read:
Sequential reads are initiated by either a current address read or a random read. If the EEPROM receives
acknowledgment “0” after 8-bit read data, the read address is incremented and the next 8-bit read data are coming out.
This operation can be continued as long as the EEPROM receives acknowledgment “0”. The address will roll over and
returns address zero if it reaches the last address of the last page. The sequential read can be continued after roll over.
The sequential read is terminated if the EEPROM receives acknowledgment “1” (no acknowledgment) and a following
stop condition.
Sequential Read Operation
128k
Start
Device
address
1010
Read data (n) Read data (n+1) Read data (n+2) Read data (n+m)
R
ACK
R/W
ACK
ACK ACK
No ACK
Stop
R10DS0008EJ0100 Rev.1.00
Aug. 04, 2010
Page 13 of 16