HN58X2508I Datasheet, PDF (15/29 Pages) Renesas Technology Corp – Electrically Erasable and Programmable Read Only Memory

HN58X2508I/HN58X2516I
Write Disable (WRDI):
One way of resetting the Write Enable Latch (WEL) bit is to send a Write Disable instruction to the device.
As shown in the following figure, to send this instruction to the device, chip select (S) is driven low, and the
bits of the instruction byte are shifted in, on serial data input (D).
The device then enters a wait state. It waits for the device to be deselected, by chip select (S) being driven
high. The Write Enable Latch (WEL) bit, in fact, becomes reset by any of the following events:

Power-up

WRDI instruction execution

WRSR instruction completion

WRITE instruction completion
Write Disable (WRDI) Sequence
V_IH
S
V_IL
V_IH
W
V_IL
V_IH
C
V_IL
V_IH
D
V_IL
Q
0 1 2 345 6 7
Instruction
High-Z
Rev.2.00, Aug.19.2004, page 15 of 27