m29dw641f STMicroelectronics, m29dw641f Datasheet - Page 36

• Manufacturer Part Number: m29dw641f
• Description: 64 Mbit 4mb X16, Multiple Bank, Boot Block 3v Supply Flash Memory
• Manufacturer: STMicroelectronics

Command interface
6.3.11
6.3.12
6.3.13
6.3.14
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Verify Standard Protection mode command
The Verify Standard Protection mode command reads the status of the Standard Protection
mode Lock bit. If it is ‘1’, the device is in Standard Protection mode.
Set Non-Volatile Modify Protection bit command
A block or group of blocks can be protected from program or erase by issuing a Set Non-
Volatile Modify Protection bit command along with the block address. This command sets
the Non-Volatile Modify Protection bit to ‘1’ for a given block or group of blocks.
Six cycles are required to issue the command:
1.
2.
3.
4.
There must be a 100µs delay between the fourth and fifth cycles.
The Non-Volatile Modify Protection bits are erased simultaneously by issuing a Clear Non-
Volatile Modify Protection bits command except if the Lock-Down bit is set to ‘1’.
The Non-Volatile Modify Protection bits can be set a maximum of 100 times.
Verify Non-volatile Modify Protection bit command
The status of a Non-Volatile Modify Protection bit for a given block or group of blocks can be
read by issuing a Verify Non-Volatile Modify Protection bit command along with the block
address.
Clear Non-volatile Modify Protection bit command
This command is used to clear all Non-Volatile Modify Protection bits. No specific block
address is required. If the Lock-Down bit is set to ‘1’, the command will fail.
Six cycles are required to issue a Clear Non-Volatile Modify Protection bits command:
1.
2.
3.
There must be a 12ms delay between the fourth and fifth cycles.
Set Lock bit command
The Set Lock bit command individually sets the Lock bit to ‘1’ for a given block or group of
blocks.
If the Non-Volatile Lock bit for the same block or group of blocks is set, the block is locked
regardless of the value of the Lock bit. (see
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 Non-
Volatile Modify Protection bit has been successfully programmed. 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 command.
The last three cycles verify if the operation has been successful. If DQ0 is set to ’1’, all
Non-Volatile Modify Protection bits have been successfully cleared. If DQ0 is ‘0’, the
operation has failed and the command must be re-issued.
Table 7: Block Protection
Table 11: Protection command
status).
M29DW641F