MBM29PL64LM SPANSION, MBM29PL64LM Datasheet - Page 23

• Manufacturer Part Number: MBM29PL64LM
• Description: Flash Memory 64 M (8M X 8/4M X 16) BIT
• Manufacturer: SPANSION

22
MBM29PL64LM
Temporary Sector Group Unprotection
Hardware Reset
Write Protect (WP)
Accelerated Program Operation
Enhanced 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
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 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
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 first 64K bytes words sectors
without using V
If the system asserts V
64K bytes / 32K 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 TIMING DIAGRAM.
The output voltage generated on the device is determined based on the V
to operate in mixed-voltage environments, driving and receiving signals to and from other devices on the same
bus.
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
CCQ
RH
ACC
Feature
” before it will allow read access. When the RESET pin is low, the devices will be in the standby
ID
from the WP/ACC pin returns the device to normal operation. Do not remove V
. This function is one of two provided by the WP/ACC pin.
ID
IH
IL
is taken away from the RESET pin, all the previously protected sector groups will be
on the WP/ACC pin, the device disables program and erase functions in the first
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
CCQ
level. This feature allows the device
ACC
from the WP/
ID
). During