ESMT
F25L04UA
Write-Enable (WREN)
The Write-Enable (WREN) instruction sets the Write-
Enable-Latch bit to 1 allowing Write operations to occur.
The WREN instruction must be executed prior to any Write
(Program/Erase) operation. CE must be driven high before the
WREN instruction is executed.
CE
0 1 2 3 4 5 6 7
MODE3
MODE0
SCK
SI
06
MSB
HIGH IMPENANCE
SO
FIGURE 11 : WRITE ENABLE (WREN) SEQUENCE
Write-Disable (WRDI)
The Write-Disable (WRDI) instruction resets the Write-Enable-Latch
bit and AAI bit to 0 disabling any new Write operations from occurring.
CE must be driven high before the WRDI instruction is executed.
CE
0 1 2 3 4 5 6 7
MODE3
MODE0
SCK
SI
04
MSB
HIGH IMPENANCE
SO
Figure 12 : WRITE DISABLE (WRDI) SEQUENCE
Enable-Write-Status-Register (EWSR)
The Enable-Write-Status-Register (EWSR) instruction arms the
Write-Status-Register (WRSR) instruction and opens the status
register for alteration. The Enable-Write-Status-Register
instruction does not have any effect and will be wasted, if it is not
followed immediately by the Write-Status-Register (WRSR)
instruction. CE must be driven low before the EWSR instruction
is entered and must be driven high before the EWSR instruction
is executed.
Elite Semiconductor Memory Technology Inc.
Publication Date: Jan. 2009
Revision: 1.2
14/25
ESMT [ ELITE SEMICONDUCTOR MEMORY TECHNOLOGY INC. ]
