m28w640fcb STMicroelectronics, m28w640fcb Datasheet - Page 29

• Manufacturer Part Number: m28w640fcb
• Description: 64 Mbit 4mb X16, Boot Block 3v Supply Flash Memory
• Manufacturer: STMicroelectronics

M28W640FCT, M28W640FCB
Table 10.
1. The lock status is defined by the write protect pin and by DQ1 (‘1’ for a locked-down block) and DQ0 (‘1’ for
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
Current State
Current Protection Status
a locked block) as read in the Read Electronic Signature command with A1 = V
1,0,1
0,0,1
1,0,0
1,1,0
1,1,1
0,0,0
0,1,1
(WP, DQ1, DQ0)
(2)
(2)
Protection status
Program/Erase
Allowed
IH
yes
yes
yes
on a locked block will restore the previous DQ0 value, giving a 111 or 110.
no
no
no
no
(1)
After Block
Command
Lock
1,0,1
1,0,1
1,1,1
1,1,1
0,0,1
0,0,1
0,1,1
After Block
Command
Unlock
Next Protection Status
1,0,0
1,0,0
1,1,0
1,1,0
0,0,0
0,0,0
0,1,1
(WP, DQ1, DQ0)
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
IH
and A0 = V
(1)
1,1,1 or 1,1,0
Block locking
IL
transition
.
After WP
0,1,1
0,0,0
0,0,1
0,1,1
1,0,0
1,0,1
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(3)