W78M32VP-XBX
The WP#/ACC pin must not be at VHH for operations other
than accelerated programming, or device damage may
result.
PROGRAM SUSPEND/PROGRAM RESUME
COMMANDS
The Program Suspend command allows the system to interrupt
an embedded programming operation or a “Write to Buffer”
programming operation so that data can read from any non-
suspended sector. When the Program Suspend command is written
during a programming process, the device halts the programming
operation within 15 μs maximum (5 μs typical) and updates the
status bits. Addresses are “don't-cares” when writing the Program
Suspend command.
It is recommended that WP#/ACC apply VHH after power-up
sequence is completed. In addition, it is recommended that
WP#/ACC apply from VHH to VIH/VIL before powering down
V
CC/VIO.
UNLOCK BYPASS
This device features an Unlock Bypass mode to facilitate shorter
programming commands. Once the device enters the Unlock
Bypass mode, only two write cycles are required to program data,
instead of the normal four cycles.
After the programming operation has been suspended, the system
can read array data from any nonsuspended sector. The Program
Suspend command may also be issued during a programming
operation while an erase is suspended. In this case, data may be
read from any addresses not within a sector in Erase Suspend or
Program Suspend. If a read is needed from the Secured Silicon
Sector area, then user must use the proper command sequences
to enter and exit this region.
This mode dispenses with the initial two unlock cycles required
in the standard program command sequence, resulting in faster
total programming time. The Command Definitions shows the
requirements for the unlock bypass command sequences.
During the unlock bypass mode, only the Read, Program, Write
Buffer Programming, Write-to-Buffer-Abort Reset, and Unlock
Bypass Reset commands are valid. To exit the unlock bypass
mode, the system must issue the two-cycle unlock bypass reset
command sequence. The first cycle must contain the sector
address and the data 90h. The second cycle need only contain
the data 00h. The sector then returns to the read mode.
The system may also write the Autoselect Command Sequence
when the device is in Program Suspend
mode. The device allows reading Autoselect codes in the
suspended sectors, since the codes are not stored in the memory
array. When the device exits the Autoselect mode, the device
reverts to Program Suspend mode, and is ready for another valid
operation. See Autoselect Section.
WRITE OPERATION STATUS
The device provides several bits to determine the status of a program
or erase operation. The following subsections describe the function of
DQ1, DQ2, DQ3, DQ5, DQ6, and DQ7.
After the Program Resume command is written, the device reverts
to programming. The system can determine the status of the
program operation using the write operation status bits, just as
in the standard program operation. See Write Operation Status
Section for more information.
DQ7: DATA# POLLING
The system must write the Program Resume command (address
bits are “don't care”) to exit the Program Suspend mode and
continue the programming operation. Further writes of the
Program Resume command are ignored. Another Program
Suspend command can be written after the device has resumed
programming.
The Data# Polling bit, DQ7, indicates to the host system whether
an Embedded Program or Erase algorithm is in progress or
completed, or whether the device is in Erase Suspend. Data#
Polling is valid after the rising edge of the final WE# pulse in the
command sequence. Note that the Data# Polling is valid only for
the last word being programmed in the write-buffer-page during
Write Buffer Programming. Reading Data# Polling status on any
word other than the last word to be programmed in the write-buffer-
page returns false status information.
ACCELERATED PROGRAM
Accelerated single word programming and write buffer programming
operations are enabled through the WP#/ACC pin. This method is
faster than the standard program command sequences.
During the Embedded Program algorithm, the device outputs on
DQ7 the complement of the datum programmed to DQ7. This
DQ7 status also applies to programming during Erase Suspend.
When the Embedded Program algorithm is complete, the device
outputs the datum programmed to DQ7. The system must provide
the program address to read valid status information on DQ7. If a
program address falls within a protected sector, Data# polling on
DQ7 is active, then that sector returns to the read mode.
NOTE
The accelerated program functions must not be used more than 10
times per sector. If the system asserts VHH on this input, the device
automatically enters the aforementioned Unlock Bypass mode and
uses the higher voltage on the input to reduce the time required for
program operations. The system can then use the Write Buffer Load
command sequence provided by the Unlock Bypass mode. Note
that if a “Write-to-Buffer-Abort Reset” is required while in Unlock
Bypass mode, the full 3-cycle RESET command sequence must
be used to reset the device. Removing VHH from the ACC input,
upon completion of the embedded program operation, returns the
device to normal operation.
During the Embedded EraseAlgorithm, Data# polling produces a “0”
on DQ7. When the Embedded Erase algorithm is complete, or if the
device enters the Erase Suspend mode, Data# Polling produces a
“1” on DQ7. The system must provide an address within any of the
sectors selected for erasure to read valid status information on DQ7.
After an erase command sequence is written, if all sectors selected
Sectors must be unlocked prior to raising WP#/ACC to VHH
.
Microsemi Corporation reserves the right to change products or specifications without notice.
August 2011 © 2011 Microsemi Corporation. All rights reserved.
Rev. 15
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