M29W320DT, M29W320DB
Command Interface
program command sequence. The memory uses the higher voltage on the V /Write
PP
Protect pin, to accelerate the Unlock Bypass Program operation.
Never raise V /Write Protect to V from any mode except Read mode, otherwise the
PP
PP
memory may be left in an indeterminate state.
4.6
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, the
Status Register is read and protected blocks cannot be programmed. Errors must be reset
using the Read/Reset command, which leaves the device in Unlock Bypass Mode. See the
Program command for details on the behavior.
4.7
4.8
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.
Chip Erase command
The Chip Erase command can be used to erase the entire chip. Six Bus Write operations
are required to issue the Chip Erase Command and start the Program/Erase Controller.
If any blocks are protected then these are ignored and all the other blocks are erased. If all
of the blocks are protected the Chip Erase operation appears to start but will terminate
within about 100µs, leaving the data unchanged. No error condition is given when protected
blocks are ignored.
During the erase operation the memory will ignore all commands, including the Erase
Suspend command. It is not possible to issue any command to abort the operation. Typical
chip erase times are given in Table 6. All Bus Read operations during the Chip Erase
operation will output the Status Register on the Data Inputs/Outputs. See the section on the
Status Register for more details.
After the Chip Erase operation has completed the memory will return to the Read Mode,
unless an error has occurred. When an error occurs the memory will continue to output the
Status Register. A Read/Reset command must be issued to reset the error condition and
return to Read Mode.
The Chip Erase Command sets all of the bits in unprotected blocks of the memory to ’1’. All
previous data is lost.
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