M29DW641F70N1 NUMONYX [Numonyx B.V], M29DW641F70N1 Datasheet - Page 35

• Manufacturer Part Number: M29DW641F70N1
• Description: 64 Mbit (4Mb x16, Multiple Bank, Page, Boot Block) 3V Supply Flash Memory
• Manufacturer: NUMONYX [Numonyx B.V]

M29DW641F
6.3.7
6.3.8
6.3.9
6.3.10
Password Protection Unlock command
The Password Protection Unlock command is used to clear the Lock-Down bit in order to
unprotect all Non-Volatile Modify Protection bits when the device is in Password Protection
mode. The Password Protection Unlock command must be issued along with the correct
Password.
The complete command sequence must be entered for each 16 bits of the Password.
There must be a 2µs delay between successive Password Protection Unlock commands in
order to prevent hackers from cracking the Password by trying all possible 64-bit
combinations. If this delay is not respected, the latest command will be ignored.
Set Password Protection mode command
The Set Password Protection mode command puts the device in Password Protection mode
by programming the Password Protection mode Lock bit to ‘1’. This command can be issued
either with the Reset/Block Temporary Unprotect pin, RP, at V
Six cycles are required to issue a Set Password Protection mode command:
1.
2.
3.
4.
There must be a 100µs delay between the fourth and fifth cycles.
Once the Password Protection mode is activated the device will permanently remain in this
mode.
Verify Password Protection mode command
The Verify Password Protection mode command reads the status of the Password
Protection mode Lock bit. If it is ‘1’, the device is in Password Protection mode.
Set Standard Protection mode command
The Set Standard Protection mode command puts the device in Standard Protection mode
by programming the Standard Protection mode Lock bit to ‘1’.
Six cycles are required to issue the Standard Protection mode command:
1.
2.
3.
4.
There must be a 100µs delay between the fourth and fifth cycles. Once the Standard
Protection mode is activated the device will permanently remain in this mode.
The first two cycles are unlock cycles.
The third cycle issues the command.
The fourth and fifth cycles select the address (see
addresses
The last cycle verifies if the operation has been successful. If DQ0 is set to ’1’, the
device has successfully entered the Password Protection mode. If DQ0 is ‘0’, the
operation has failed and the command must be re-issued.
The first two cycles are unlock cycles.
The third cycle issues the program command.
The fourth and fifth cycles select the address (see
addresses
The last cycle verifies if the operation has been successful. If DQ0 is set to ’1’, the
Standard Protection mode has been successfully activated. If DQ0 is ‘0’, the operation
has failed and the command must be re-issued.
).
).
Table 11: Protection command
Table 11: Protection command
ID
or at V
Command interface
IH
.
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