R1EX25512ASA00A Datasheet, PDF (11/22 Pages) Renesas Technology Corp – Serial Peripheral Interface 512K EEPROM (64-Kword × 8-bit)

R1EX25512ASA00A/R1EX25512ATA00A
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
0 1 2 345 6 7
Instruction
Q
High-Z
R10DS0046EJ0200 Rev.2.00
Oct.04, 2010
Page 11 of 20