M29W256GH7AN6E NUMONYX, M29W256GH7AN6E Datasheet - Page 91

• Manufacturer Part Number: M29W256GH7AN6E
• Description: Flash Mem Parallel 3V/3.3V 256M-Bit 32M x 8/16M x 16 70ns 56-Pin TSOP Tray
• Manufacturer: NUMONYX

Specifications of M29W256GH7AN6E

• Package: 56TSOP
• Cell Type: NOR
• Density: 256 Mb
• Architecture: Sectored
• Block Organization: Symmetrical
• Location Of Boot Block: Bottom|Top
• Typical Operating Supply Voltage: 3|3.3 V
• Sector Size: 128KByte x 256
• Timing Type: Asynchronous
• Operating Temperature: -40 to 85 °C
• Interface Type: Parallel

Appendix C
C.1
The M29W256GH/L has an extra block, the extended memory block, that can be accessed
using a dedicated command. This extended memory block is 128 words in x 16 mode and
256 bytes in x 8 mode. It is used as a security block (to provide a permanent security
identification number) or to store additional information.
The device can be shipped either with the extended memory block factory locked, or factory
unlocked.
The extended memory block cannot be erased, and is one-time programmable (OTP)
memory. If memory block is factory locked or customer protected by setting the extended
memory block protection bit, it cannot be further modified.
If the extended memory block is not factory locked, it can be customer lockable. Its status is
indicated by bit DQ7 in autoselect mode. This bit is permanently set to either ‘1’ or ‘0’ at the
factory and cannot be changed. When set to ‘1’, it indicates that the device is factory locked
and the extended memory block is protected. When set to ‘0’, it indicates that the device is
customer lockable. Bit DQ7 being permanently locked to either ‘1’ or ‘0’ is another security
feature which ensures that a customer lockable device cannot be used instead of a factory
locked one.
Bit DQ7 is the most significant bit in the extended memory block verify indicator. It can be
read in auto select mode using either the programmer (see
system method (see
The extended memory block can only be accessed when the device is in extended memory
block mode. For details of how the extended memory block mode is entered and exited,
refer to the
Factory locked extended memory block
In devices where the extended memory block is factory locked, the security identification
number is written to the extended memory block address space (see
memory block address and
memory block cannot be unprotected.
Section 6.4.2: Extended Memory Block
Extended memory block
Table 12
data) in the factory. The DQ7 bit is set to ‘1’ and the extended
and
Table
13).
and to
Table 19
Table 8
and
and
Table 45: Extended
Table
Table
20.
9) or the in-
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