Command Interface
M29W640GH, M29W640GL, M29W640GT, M29W640GB
4.2.5
Quadruple Word Program command
This is used to write a page of four adjacent words (or 8 adjacent bytes), in x16 mode,
simultaneously. The addresses of the four words must differ only in A1 and A0.
12V must be applied to the V /Write Protect pin, V /WP, prior to issuing a Quadruple Byte
PP
PP
Program command. Care must be taken because applying a 12V voltage to the V /WP pin
PP
will temporarily unprotect any protected block.
Five bus write cycles are necessary to issue the command:
●
●
●
●
●
The first bus cycle sets up the command.
The second bus cycle latches the Address and the Data of the first word to be written.
The third bus cycle latches the Address and the Data of the second word to be written.
The fourth bus cycle latches the Address and the Data of the third word to be written.
The fifth bus cycle latches the Address and the Data of the fourth word to be written
and starts the Program/Erase Controller.
4.2.6
Unlock Bypass command
The Unlock Bypass command is used in conjunction with the Unlock Bypass Program
command to program the memory faster than with the standard program commands. When
the cycle time to the device is long, considerable time saving can be made by using these
commands. Three Bus Write operations are required to issue the Unlock Bypass command.
Once the Unlock Bypass command has been issued the memory will only accept the Unlock
Bypass Program command and the Unlock Bypass Reset command. The memory can be
read as if in Read mode.
When V is applied to the V /Write Protect pin the memory automatically enters the
PP
PP
Unlock Bypass mode and the Unlock Bypass Program command can be issued
immediately.
4.2.7
Unlock Bypass Program command
The Unlock Bypass command is used in conjunction with the Unlock Bypass Program
command to program the memory. When the cycle time to the device is long, considerable
time saving can be made by using these commands. Three Bus Write operations are
required to issue the Unlock Bypass command.
Once the Unlock Bypass command has been issued the memory will only accept the Unlock
Bypass Program command and the Unlock Bypass Reset command. The memory can be
read as if in Read mode.
The memory offers accelerated program operations through the V /Write Protect pin.
PP
When the system asserts V on the V /Write Protect pin, the memory automatically
PP
PP
enters the Unlock Bypass mode. The system may then write the two-cycle Unlock Bypass
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.
30/90
NUMONYX [ NUMONYX B.V ]
