M28W640FCT STMICROELECTRONICS [STMicroelectronics], M28W640FCT Datasheet - Page 18

• Manufacturer Part Number: M28W640FCT
• Description: 64 Mbit (4Mb x16, Boot Block) 3V Supply Flash Memory
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M28W640FCT, M28W640FCB
Table 9. Block Lock Status
Table 10. Protection Status
Note: 1. The lock status is defined by the write protect pin and by DQ1 (‘1’ for a locked-down block) and DQ0 (‘1’ for a locked block) as read
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Current State
Current Protection Status
2. All blocks are locked at power-up, so the default configuration is 001 or 101 according to WP status.
3. A WP transition to V
1,0,1
0,0,1
1,0,0
1,1,0
1,1,1
0,0,0
0,1,1
in the Read Electronic Signature command with A1 = V
(WP, DQ1, DQ0)
(2)
(2)
Block Lock Configuration
Block is Locked-Down
Program/Erase
Block is Unlocked
Block is Locked
Allowed
IH
yes
yes
yes
on a locked block will restore the previous DQ0 value, giving a 111 or 110.
no
no
no
no
Item
(1)
Lock Command
After Block
1,0,1
1,0,1
1,1,1
1,1,1
0,0,1
0,0,1
0,1,1
IH
and A0 = V
After Block
Command
Unlock
1,0,0
1,0,0
1,1,0
1,1,0
0,0,0
0,0,0
0,1,1
Next Protection Status
IL
.
(WP, DQ1, DQ0)
Address
xx002
After Block Lock-
Down Command
1,1,1
1,1,1
1,1,1
1,1,1
0,1,1
0,1,1
0,1,1
(1)
DQ0=0
DQ0=1
DQ1=1
1,1,1 or 1,1,0
LOCK
Data
transition
After WP
0,0,0
0,0,1
0,1,1
0,1,1
1,0,0
1,0,1
(3)