MBM29PL32BM Fujitsu Media Devices, MBM29PL32BM Datasheet - Page 24

• Manufacturer Part Number: MBM29PL32BM
• Description: (MBM29PL32TM/BM) FLASH MEMORY CMOS 32 M (4M X 8/2M X 16) BIT MirrorFlash
• Manufacturer: Fujitsu Media Devices

24
MBM29PL32TM/BM
Temporary Sector Group Unprotection
Hardware Reset
Write Protect (WP)
Accelerated Program Operation
This feature allows temporary unprotection of previously protected sector groups of the devices in order to change
data. The Sector Group Unprotection mode is activated by setting the RESET pin to high voltage (V
this mode, formerly protected sector groups can be programmed or erased by selecting the sector group ad-
dresses. Once the V
protected again. Refer to “Temporary Sector Group Unprotection Timing Diagram” in
FORMS and “Temporary Sector Group Unprotection Algorithm” in FLOW CHART.
The devices may be reset by driving the RESET pin to V
and has to be kept low (V
in the process of being executed will be terminated and the internal state machine will be reset to the read mode
“t
additional “t
mode for the duration of the pulse and all the data output pins will be tri-stated. If a hardware reset occurs during
a program or erase operation, the data at that particular location will be corrupted.
The Write Protection function provides a hardware method of protecting certain outermost 8K bytes / 4K words
sectors without using V
If the system asserts V
8K bytes / 4K words sectors independently of whether this sector was protected or unprotected using the method
described in “Sector Group Protection" above.
If the system asserts V
sectors were last set to be protected to the unprotected status. Sector protection or unprotection for this sector
depends on whether this was last protected or unprotected using the method described in “Sector protection/
unprotection”.
The device offers accelerated program operation which enables programming in high speed. If the system asserts
V
operation will reduce to about 85%. This function is primarily intended to allow high speed programing, so caution
is needed as the sector group becomes temporarily unprotected.
The system would use a fast program command sequence when programming during acceleration mode. Set
command to fast mode and reset command from fast mode are not necessary. When the device enters the
acceleration mode, the device is automatically set to fast mode. Therefore, the present sequence could be used
for programming and detection of completion during acceleration mode.
Removing V
ACC pin while programming. See “Accelerated Program Timing Diagram” in SWITCHING WAVEFORM.
READY
ACC
to the WP/ACC pin, the device automatically enters the acceleration mode and the time required for program
” after the RESET pin is driven low. Furthermore, once the RESET pin goes high, the devices require an
RH
ACC
” before it will allow read access. When the RESET pin is low, the devices will be in the standby
from the WP/ACC pin returns the device to normal operation. Do not remove V
ID
IL
IH
is taken away from the RESET pin, all the previously protected sector groups will be
ID
. This function is one of two provided by the WP/ACC pin.
on the WP/ACC pin, the device disables program and erase functions in the outermost
on the WP/ACC pin, the device reverts of whether the outermost 8K bytes / 4K words
IL
) for at least “t
90/10
RP
” in order to properly reset the internal state machine. Any operation
IL
from V
IH
. The RESET pin has a pulse requirement
SWITCHING WAVE-
ACC
from the WP/
ID
). During