m29dw128g60nf6e Numonyx, m29dw128g60nf6e Datasheet - Page 38

• Manufacturer Part Number: m29dw128g60nf6e
• Description: 128-mbit 8 Mbit X16, Multiple Bank, Page, Dual Boot 3 V Supply Flash Memory
• Manufacturer: Numonyx

Command interface
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Once password program operation has completed, an Exit Protection Command Set
command must be issued to return the device to read mode. The password protection mode
can then be selected.
By default, all password bits are set to ‘1’.
Password Read command
The Password Read command is used to verify the password used in password protection
mode.
To verify the 64-bit password, the complete command sequence must be entered four times
at four consecutive addresses selected by A1-A0.
If the password mode lock bit is programmed and the user attempts to read the password,
the device will output FFh onto the I/O data bus.
An Exit Protection Command Set command must be issued to return the device to read
mode.
Password Unlock command
The Password Unlock command is used to clear the NVPB lock bit allowing to modify the
NVPBs.
The Password Unlock command must be issued along with the correct password.
There must be a 1 µs delay between successive password 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.
Approximately 1 µs is required for unlocking the device after the valid 64-bit password has
been provided.
Non-volatile protection mode command set
Enter Non-volatile Protection Command Set command
Three bus write cycles are required to issue the Enter Non-volatile Protection Command Set
command. Once the command has been issued, the commands related to the non-volatile
protection mode can be issued to the device.
Non-volatile Protection Bit Program command (NVPB Program)
A block can be protected from program or erase by issuing a Non-volatile Protection Bit
command along with the block address. This command sets the NVPB to ‘1’ for a given
block.
Read Non-volatile Protection Bit Status command (Read NVPB Status)
The status of a NVPB for a given block or group of blocks can be read by issuing a Read
Non-Volatile Modify Protection Bit command along with the block address.
Clear all Non-volatile Protection Bits command (Clear all NVPBs)
The NVPBs are erased simultaneously by issuing a Clear all Non-volatile Protection Bits
command. No specific block address is required. If the NVPB lock bit is set to ‘0’, the
command fails.
M29DW128G