256Mb: 3V Embedded Parallel NOR Flash
Program Operations
The PROGRAM SUSPEND command may also be issued during a PROGRAM operation
while an erase is suspended. In this case, data may be read from any address not in
erase suspend or program suspend mode. To read from the extended memory block
area (one-time programmable area), the ENTER/EXIT EXTENDED MEMORY BLOCK
command sequences must be issued.
The system may also issue the AUTO SELECT command sequence when the device is in
program suspend mode. The system can read as many auto select codes as required.
When the device exits auto select mode, the device reverts to program suspend mode
and is ready for another valid operation.
The PROGRAM SUSPEND operation is aborted by performing a device reset or power-
down. In this case, data integrity cannot be ensured, and it is recommended that the
words or bytes that were aborted be reprogrammed.
PROGRAM RESUME Command
The PROGRAM RESUME (30h) command must be issued to exit a program suspend
mode and resume a PROGRAM operation. The controller can use DQ7 or DQ6 status
bits to determine the status of the PROGRAM operation. After a PROGRAM RESUME
command is issued, subsequent PROGRAM RESUME commands are ignored. Another
PROGRAM SUSPEND command can be issued after the device has resumed program-
ming.
ENTER and EXIT ENHANCED BUFFERED PROGRAM Command
The Enhanced Buffered Program commands are available only in x16 mode. When the
ENTER ENHANCED BUFFERED PROGRAM command is issued, the device accepts on-
ly these commands, which can be executed multiple times. To ensure successful com-
pletion of the ENTER ENHANCED BUFFERED PROGRAM command, it is recommen-
ded that users monitor the toggle bit. The EXIT ENHANCED BUFFERED PROGRAM
command returns the device to read mode; two bus write operations are required to is-
sue the command.
ENHANCED BUFFERED PROGRAM Command
The ENHANCED BUFFERED PROGRAM command makes use of a 256-word write buf-
fer to speed up programming. Each write buffer has the same A23-A8 addresses. This
command dramatically reduces system programming time compared to both the
standard non-buffered PROGRAM command and the WRITE TO BUFFER command.
When issuing the ENHANCED BUFFERED PROGRAM command, the VPP/WP pin can
be held HIGH or raised to VPPH (see Program/Erase Characteristics). The following suc-
cessive steps are required to issue the WRITE TO BUFFER PROGRAM command:
First, the ENTER ENHANCED BUFFERED PROGRAM command issued. Next, one bus
WRITE cycle sets up the ENHANCED BUFFERED PROGRAM command. The set-up
code can be addressed to any location within the targeted block. Then, a second bus
WRITE cycle loads the first address and data to be programmed. There are a total of 256
address and data loading cycles. When the 256 words are loaded to the buffer, a third
WRITE cycle programs the content of the buffer. Last, when the command completes,
the EXIT ENHANCED BUFFERED PROGRAM command is issued.
Address/data cycles must be loaded in an increasing address order, from A[7:0] =
00000000 to A[7:0] = 11111111 until all 256 words are loaded. Invalid address combina-
PDF: 09005aef84bd3b68
m29w_256mb.pdf - Rev. B 5/13 EN
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