256Mb: 3V Embedded Parallel NOR Flash
Protection Operations
Figure 11: Program/Erase Nonvolatile Protection Bit Algorithm
Start
ENTER Nonvolatile
Protection
COMMAND SET
PROGRAM Nonvolatile
Protection Bit
Addr = BAd
Read byte twice
Addr = BAd
No
DQ6 = Toggle
Yes
No
DQ5 = 1
Yes
Wait 500µs
Read byte twice
Addr = BAd
No
Read byte twice
Addr = BAd
DQ6 = Toggle
Yes
DQ0 =
1 (erase)
0 (program)
No
Yes
Fail
Reset
Pass
EXIT PROTECTION
COMMAND SET
NONVOLATILE PROTECTION BIT LOCK BIT Commands
After the ENTER NONVOLATILE PROTECTION BIT LOCK BIT COMMAND SET (50h)
command has been issued, the commands that allow the nonvolatile protection bit lock
bit to be set can be issued to the device. This command requires three bus write cycles.
The PROGRAM NONVOLATILE PROTECTION BIT LOCK BIT (A0h) command is used to
set the nonvolatile protection bit lock bit to 0, thus locking the nonvolatile protection
bits and preventing them from being modified.
PDF: 09005aef84ecabef
m29dw_256g.pdf - Rev. A 10/12 EN
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