M29W640FT70N6E Micron Technology Inc, M29W640FT70N6E Datasheet - Page 62

• Manufacturer Part Number: M29W640FT70N6E
• Manufacturer: Micron Technology Inc

Specifications of M29W640FT70N6E

• Cell Type: NOR
• Density: 64Mb
• Access Time (max): 70ns
• Interface Type: Parallel
• Boot Type: Top
• Address Bus: 23/22Bit
• Operating Supply Voltage (typ): 3/3.3V
• Operating Temp Range: -40C to 85C
• Package Type: TSOP
• Sync/async: Asynchronous
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (min): 2.7V
• Operating Supply Voltage (max): 3.6V
• Word Size: 8/16Bit
• Number Of Words: 8M/4M
• Supply Current: 10mA
• Mounting: Surface Mount
• Pin Count: 48
• Lead Free Status / Rohs Status: Compliant

Appendix C
C.1
C.2
62/71
The M29W640F has an extra block, the Extended Block, that can be accessed using a
dedicated command.
This Extended Block is 128 Words in x16 mode and 256 Bytes in x8 mode. It is used as a
security block to provide a permanent security identification number) or to store additional
information.
The Extended Block is either Factory Locked or Customer Lockable, its status is indicated
by bit DQ7. 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
Block is protected. When set to ‘0’, it indicates that the device is customer lockable and the
Extended Block is unprotected. 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 Block Verify Code and a specific
procedure must be followed to read it. See “Extended Memory Block Verify Code
Bus operations, BYTE = V
read bit DQ7.
The Extended 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
Enter Extended Block command
Table 6
Factory Locked Extended Block
In devices where the Extended Block is factory locked, the Security Identification Number is
written to the Extended Block address space (see
data) in the factory. The DQ7 bit is set to ‘1’ and the Extended Block cannot be unprotected.
Customer Lockable Extended Block
A device where the Extended Block is customer lockable is delivered with the DQ7 bit set to
‘0’ and the Extended Block unprotected. It is up to the customer to program and protect the
Extended Block but care must be taken because the protection of the Extended Block is not
reversible.
There are two ways of protecting the Extended Block:
Once the Extended Block is programmed and protected, the Exit Extended Block command
must be issued to exit the Extended Block mode and return the device to Read mode.
Issue the Enter Extended Block command to place the device in Extended Block mode,
then use the In-System Technique with RP either at V
Section D.2: In-System technique
Figure
Issue the Enter Extended Block command to place the device in Extended Block mode,
then use the Programmer Technique (refer to
technique
explanation of the technique).
and
19, for a detailed explanation of the technique).
Table 7: Commands, 8-bit mode, BYTE = V
Extended Memory Block
and to the corresponding flowcharts,
IL
and
Table 5: Bus operations, BYTE = V
and
Section 4.3.2: Exit Extended Block
and to the corresponding flowcharts,
Table 29: Extended Block address and
Appendix
Figure 16
IL
.
IH
D,
or at V
and
Section D.1: Programmer
Figure
ID
IH
, for details of how to
(refer to
command, and to
17, for a detailed
Section 4.3.1:
Figure 18
Appendix
” in
Table 4:
and
D,