MBM29PL12LM Fujitsu Media Devices, MBM29PL12LM Datasheet - Page 27

• Manufacturer Part Number: MBM29PL12LM
• Description: FLASH MEMORY 128 M (16M x 8/8M x 16) BIT
• Manufacturer: Fujitsu Media Devices

Temporary Sector Group Unprotection
Hardware Reset
Write Protect (WP)
Accelerated Program Operation
V
voltage.
CCQ
V
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
During this mode, formerly protected sector groups can be programmed or erased by selecting the sector group
addresses. Once the V
protected again. Refer to “Temporary Sector Group Unprotection Timing Diagram” in ■TIMING DIAGRAM 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
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.
Furthermore, once the RESET pin goes high, the devices require an additional “t
access.
The Write Protection function provides a hardware method of protecting certain first 64K bytes / 32K words
sector without using V
If the system asserts V
bytes / 32K words sector 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 command and 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 ■TIMING DIAGRAM.
CCQ
READY
ACC
determines the MBM29PL12LM voltage output. V
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. When the RESET pin is low, the devices will be in the standby mode
ACC
from the WP/ACC pin returns the device to normal operation. Do not remove V
ID
ID
IL
. This function is one of two provided by the WP/ACC pin.
IH
on the WP/ACC pin, the device disables program and erase functions in the first 64K
is taken away from the RESET pin, all the previously protected sector groups will be
IL
on the WP/ACC pin, the device reverts of whether the first 64K bytes / 32K words
) for at least “t
RP
” in order to properly reset the internal state machine. Any operation
CCQ
facilitates signal exchange within devices that operate in different
IL
from V
IH
. The RESET pin has a pulse requirement
MBM29PL12LM
RH
” before it will allow read
ACC
from the WP/
ID
10
).
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