hn58x24256as Renesas Electronics Corporation., hn58x24256as Datasheet - Page 15

• Manufacturer Part Number: hn58x24256as
• Description: Two-wire Serial Interface 256k Eeprom 32-kword ?? 8-bit
• Manufacturer: Renesas Electronics Corporation.

HN58X24256AS
Read Operation
There are three read operations: current address read, random read, and sequential read. Read operations
are initiated the same way as write operations with the exception of R/W = “1”.
Current Address Read:
The internal address counter maintains the last address accessed during the last read or write operation,
with incremented by one. Current address read accesses the address kept by the internal address counter.
After receiving a start condition and the device address word (R/W is “1”), the EEPROM outputs the 8-bit
current address data from the most significant bit following acknowledgment “0”. If the EEPROM
receives acknowledgment “1” (no acknowledgment) and a following stop condition, the EEPROM stops
the read operation and is turned to a standby state. In case the EEPROM has accessed the last address of
the last page at previous read operation, the current address will roll over and returns to zero address. In
case the EEPROM has accessed the last address of the page at previous write operation, the current address
will roll over within page addressing and returns to the first address in the same page. The current address
is valid while power is on. The current address after power on will be indefinite. The random read
operation described below is necessary to define the memory address.
Current Address Read Operation
Rev.0.01, Mar.22.2007, page 15 of 20
256k
Start
1 0 1 0
Device
address
R
R/W
Read data (n+1)
ACK
No ACK
Stop