HN58V65AI/HN58V66AI/HN58V65A-SR/HN58V66A-SR Series

Rev.3.00, Feb.02.2004, page 19 of 26

Functional Description

Automatic Page Write

Page-mode write feature allows 1 to 64 bytes of data to be written into the EEPROM in a single write

cycle. Following the initial byte cycle, an additional 1 to 63 bytes can be written in the same manner. Each

additional byte load cycle must be started within 30

µs from the preceding falling edge of WE or CE. When

CE or WE is kept high for 100 µs after data input, the EEPROM enters write mode automatically and the

input data are written into the EEPROM.

Data Polling

Data polling indicates the status that the EEPROM is in a write cycle or not. If EEPROM is set to read

mode during a write cycle, an inversion of the last byte of data outputs from I/O7 to indicate that the

EEPROM is performing a write operation.

RDY/

Busy Signal

RDY/

Busy signal also allows status of the EEPROM to be determined. The RDY/Busy signal has high

cycle, the RDY/

Busy signal changes state to high impedance.

RES Signal (only the HN58V66A series)

When

RES is low, the EEPROM cannot be read or programmed. Therefore, data can be protected by

keeping

RES low when V

doesn’t provide a latch function.

V

Program inhibit

CC

RES

Program inhibit

Read inhibit

Read inhibit