25lc512 Microchip Technology Inc., 25lc512 Datasheet - Page 11

• Manufacturer Part Number: 25lc512
• Description: 512 Kbit Spi Bus Serial Eeprom
• Manufacturer: Microchip Technology Inc.

2.3
The 25AA512 contains a write enable latch.
Table 2-4 for the Write-Protect Functionality Matrix.
This latch must be set before any write operation will be
completed internally. The WREN instruction will set the
latch, and the WRDI will reset the latch.
The following is a list of conditions under which the
write enable latch will be reset:
FIGURE 2-4:
FIGURE 2-5:
© 2007 Microchip Technology Inc.
Write Enable (WREN) and Write
Disable (WRDI)
WRITE ENABLE SEQUENCE (WREN)
WRITE DISABLE SEQUENCE (WRDI)
SCK
CS
SO
SCK
SI
CS
SO
SI
0
0
0
0
0
1
0
1
See
Preliminary
High-Impedance
0
High-Impedance
0
2
2
0
0
3
3
• Power-up
• WRDI instruction successfully executed
• WRSR instruction successfully executed
• WRITE instruction successfully executed
• PE instruction successfully executed
• SE instruction successfully executed
• CE instruction successfully executed
0
0
4
4
1
5
1
5
1
6
1 0
6
0
7
0
7
25AA512
DS22021C-page 11