m29dw256g Numonyx, m29dw256g Datasheet - Page 80

• Manufacturer Part Number: m29dw256g
• Description: 256-mbit X16, Multiple Bank, Page, Dual Boot 3 V Supply Flash Memory
• Manufacturer: Numonyx

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Customer lockable extended memory block
A device where the extended memory block is customer lockable is delivered with the DQ7
bit set to ‘0’ and the extended memory block unprotected. It is up to the customer to
program and protect the extended memory block but care must be taken because the
protection of the extended memory block is not reversible.
If the device has not been shipped with the extended memory block factory protected, the
block can be protected by setting the extended memory block protection bit, DQ0, to ‘0’.
However, this bit is one-time programmable and once protected the extended memory block
cannot be unprotected.
Once the extended memory block is programmed, the Exit Extended Memory Block
command must be issued to exit the extended memory block mode and return the device to
read mode.
Table 41.
1. See
Addresses, Bank
000000h-00007Fh
Table 32: Block Addresses, Bank
Address
x16
Extended memory block address and data
(1)
C.
Security identification number
A,
Factory locked
Table 33: Block Addresses, Bank
Data
B, and
Determined by customer
Customer lockable
Table 34: Block