M29DW128F60NF1 STMICROELECTRONICS [STMicroelectronics], M29DW128F60NF1 Datasheet - Page 84

• Manufacturer Part Number: M29DW128F60NF1
• Description: 128 Mbit (16Mb x8 or 8Mb x16, Multiple Bank, Page, Boot Block) 3V Supply, Flash Memory
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

12 Part numbering
Appendix D High Voltage Block Protection
D.1
D.2
84/93
The High Voltage Block Protection can be used to prevent any operation from modifying the
data stored in the memory. The blocks are protected in groups, refer to
details of the Protection Groups. Once protected, Program and Erase operations within the
protected group fail to change the data.
There are three techniques that can be used to control Block Protection, these are the
Programmer technique, the In-System technique and Temporary Unprotection. Temporary
Unprotection is controlled by the Reset/Block Temporary Unprotection pin, RP; this is described
in the Signal Descriptions section.
To protect the Extended Block issue the Enter Extended Block command and then use either
the Programmer or In-System technique. Once protected issue the Exit Extended Block
command to return to read mode. The Extended Block protection is irreversible, once protected
the protection cannot be undone.
Programmer Technique
The Programmer technique uses high (V
cannot be achieved using a standard microprocessor bus, therefore the technique is
recommended only for use in Programming Equipment.
To protect a group of blocks follow the flowchart in
Protect
then all groups can be unprotected at the same time. To unprotect the chip follow
Programmer Equipment Chip Unprotect
Operations, 8-bit or 16-bit
The timing on these flowcharts is critical. Care should be taken to ensure that, where a pause is
specified, it is followed as closely as possible. Do not abort the procedure before reaching the
end. Chip Unprotect can take several seconds and a user message should be provided to show
that the operation is progressing.
In-System Technique
The In-System technique requires a high voltage level on the Reset/Blocks Temporary
Unprotect pin, RP
components on the microprocessor bus, therefore this technique is suitable for use after the
memory has been fitted to the system.
To protect a group of blocks follow the flowchart in
Protect
then all the groups can be unprotected at the same time. To unprotect the chip follow
In-System Equipment Chip Unprotect
The timing on these flowcharts is critical. Care should be taken to ensure that, where a pause is
specified, it is followed as closely as possible. Do not allow the microprocessor to service
interrupts that will upset the timing and do not abort the procedure before reaching the end.
Chip Unprotect can take several seconds and a user message should be provided to show that
the operation is progressing.
Flowchart. To unprotect the whole chip it is necessary to protect all of the groups first,
Flowchart. To unprotect the whole chip it is necessary to protect all of the groups first,
(1)
. This can be achieved without violating the maximum ratings of the
Mode, gives a summary of each operation.
Flowchart.
Flowchart.
ID
) voltage levels on some of the bus pins. These
Figure 23: Programmer Equipment Group
Figure 25: In-System Equipment Group
Table 42: Programmer Technique Bus
Appendix
A,
M29DW128F
Figure 24:
Table 34
Figure 26:
for