m29w400b-100za6tr STMicroelectronics, m29w400b-100za6tr Datasheet - Page 28

• Manufacturer Part Number: m29w400b-100za6tr
• Description: 64 Mbit 8mb X8 Or 4mb X16, Multiple Bank, Boot Block 3v Supply Flash Memory
• Manufacturer: STMicroelectronics

Command interface
4.2.7
4.2.8
4.3
4.3.1
4.3.2
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When V
Unlock Bypass mode and the Unlock Bypass Program command can be issued
immediately.
Unlock Bypass Program command
The Unlock Bypass Program command can be used to program one address in the memory
array at a time. The command requires two Bus Write operations, the final write operation
latches the address and data in the internal state machine and starts the Program/Erase
Controller.
The Program operation using the Unlock Bypass Program command behaves identically to
the Program operation using the Program command. The operation cannot be aborted, a
Bus Read operation to the Bank where the command was issued outputs the Status
Register. See the Program command for details on the behavior.
Unlock Bypass Reset command
The Unlock Bypass Reset command can be used to return to Read/Reset mode from
Unlock Bypass Mode. Two Bus Write operations are required to issue the Unlock Bypass
Reset command. Read/Reset command does not exit from Unlock Bypass Mode.
Block Protection commands
Enter Extended Block command
The M29DW640F has one extra 256-Byte block (Extended Block) that can only be accessed
using the Enter Extended Block command. Three Bus write cycles are required to issue the
Extended Block command. Once the command has been issued the device enters
Extended Block mode where all Bus Read or Program operations to the 000000h-00007Fh
(Word) or 000000h-0000FFh (Byte) addresses access the Extended Block. The Extended
Block cannot be erased, and can be treated as one-time programmable (OTP) memory. In
Extended Block mode only array cell locations (Bank A) with the same addresses as the
Extended Block (000000h-00007Fh (Word) or 000000h-0000FFh (Byte)) are not accessible.
In Extended Block mode dual operations are allowed and the Extended Block physically
belongs to Bank A.
When in Extended Block mode, Erase, Chip Erase, Erase Suspend and Erase resume
commands are not allowed.
To exit from the Extended Block mode the Exit Extended Block command must be issued.
The Extended Block can be protected, however once protected the protection cannot be
undone.
Exit Extended Block command
The Exit Extended Block command is used to exit from the Extended Block mode and return
the device to Read mode. Four Bus Write operations are required to issue the command.
PP
is applied to the V
PP
/Write Protect pin the memory automatically enters the
M29DW640F