25AA512/25LC512
• Power-up
2.3
Write Enable (WREN) and Write
Disable (WRDI)
• WRDIinstruction successfully executed
• WRSRinstruction successfully executed
• WRITEinstruction successfully executed
• PEinstruction successfully executed
• SEinstruction successfully executed
• CEinstruction successfully executed
The 25XX512 contains a write enable latch.
See
Table 2-4 for the Write-Protect Functionality Matrix.
This latch must be set before any write operation will be
completed internally. The WRENinstruction will set the
latch, and the WRDIwill reset the latch.
The following is a list of conditions under which the
write enable latch will be reset:
FIGURE 2-4:
WRITE ENABLE SEQUENCE (WREN)
CS
SCK
SI
0
1
2
3
4
5
6
7
0
0
0
0
0
1
1
0
High-Impedance
SO
FIGURE 2-5:
WRITE DISABLE SEQUENCE (WRDI)
CS
0
1
2
3
4
5
6
7
SCK
0
1
0
0
0
0
0
1
0
SI
High-Impedance
SO
DS22021B-page 10
Preliminary
© 2007 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
