m29dw128g60nf6e Numonyx, m29dw128g60nf6e Datasheet - Page 78

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

Extended memory block
Appendix C
C.1
78/85
The M29DW128G has an extra block, the extended memory block, that can be accessed
using a dedicated command. This extended memory block is 256 words. It is used as a
security block (to provide a permanent security identification number) or to store additional
information.
The extended memory block is divided into two memory areas of 128 words each:
Bits DQ6 and DQ7 are the most significant bits in the extended block protection indicator
and a specific procedure must be followed to read it. See
memory block protection indicator
DQ7.
The extended memory block can only be accessed when the device is in extended block
mode. For details of how the extended block mode is entered and exited, refer to the
Section 7.1.10: Program command
command, and to
Factory locked section of extended memory block
The first section of the extended memory block is permanently protected from program
operations and cannot be unprotected. The random number, electronic serial number (ESN)
and security identification number (see
data) are written in this section in the factory.
The first one is factory locked.
The second one is customer lockable. It is up to the customer to protect it from program
operations. Its status is indicated by bit DQ6 and DQ7. When DQ7 is set to ‘1’ and DQ6
to ‘0’, it indicates that this second memory area is customer lockable. When DQ7 and
DQ6 are both set to ‘1’, it indicates that the second part of the extended memory block
is customer locked and protected from program operations.
Extended memory block
Table 11: Block protection
and
and
Table 6: Block protection
Table 38: Extended memory block address and
Section 7.3.2: Exit Extended Memory Block
commands.
Section 4.0.2: Verify extended
for details of how to read bit
M29DW128G