Rev.2.00, Aug.19.2004, page 15 of 27
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:
WRDI instruction execution
WRSR instruction completion
WRITE instruction completion
Write Disable (WRDI) Sequence