M25PE10, M25PE20
Write Enable (WREN)
The Write Enable (WREN) instruction (Figure 8.)
sets the Write Enable Latch (WEL) bit.
The Write Enable Latch (WEL) bit must be set pri-
or to every Page Write (PW), Page Program (PP),
Page Erase (PE), and Sector Erase (SE) instruc-
tion.
The Write Enable (WREN) instruction is entered
by driving Chip Select (S) Low, sending the in-
struction code, and then driving Chip Select (S)
High.
Figure 8. Write Enable (WREN) Instruction Sequence
S
0
1
2
3
4
5
6
7
C
D
Q
Instruction
High Impedance
AI02281E
Write Disable (WRDI)
The Write Disable (WRDI) instruction (Figure 9.)
resets the Write Enable Latch (WEL) bit.
The Write Disable (WRDI) instruction is entered by
driving Chip Select (S) Low, sending the instruc-
tion code, and then driving Chip Select (S) High.
The Write Enable Latch (WEL) bit is reset under
the following conditions:
–
–
–
–
–
–
Power-up
Write Disable (WRDI) instruction completion
Page Write (PW) instruction completion
Page Program (PP) instruction completion
Page Erase (PE) instruction completion
Sector Erase (SE) instruction completion
Figure 9. Write Disable (WRDI) Instruction Sequence
S
0
1
2
3
4
5
6
7
C
D
Q
Instruction
High Impedance
AI03750D
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STMICROELECTRONICS [ ST ]
