MBM29DL640E Fujitsu Microelectronics, Inc., MBM29DL640E Datasheet - Page 27

• Manufacturer Part Number: MBM29DL640E
• Description: Flash Memory 64 M 8 M X 8/4 M X 16 Bit Dual Operation
• Manufacturer: Fujitsu Microelectronics, Inc.

RESET
Hardware Reset
Boot Block Sector Protection
Accelerated Program Operation
The device may be reset by driving the RESET pin to V
be kept low (V
of being executed will be terminated and the internal state machine will be reset to the read mode “t
the RESET pin is driven low. Furthermore, once the RESET pin goes high the device requires an additional “t
before it will allow read access. When the RESET pin is low, the device will be in the standby 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. Please note that the RY/BY output signal
should be ignored during the RESET pulse. See Figure 14 for the timing diagram. Refer to Temporary Sector
Group Unprotection for additional functionality.
The Write Protection function provides a hardware method of protecting certain boot sectors without using V
This function is one of two provided by the WP/ACC pin.
If the system asserts V
outermost 8 Kbytes on both ends of boot sectors independently of whether those sectors are protected or
unprotected using the method described in “Sector Protection/Unprotection.”
If the system asserts V
ends of boot sectors were last set to be protected or unprotected. Sector protection or unprotection for these
four sectors depends on whether they were 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 60 . This function is primarily intended to allow high speed programming, so
caution is needed as the sector group will temporarily be 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 Figure 21.
(MBM29DL640E : SA0, SA1, SA140, and SA141)
ACC
to the WP/ACC pin, the device automatically enters the acceleration mode and the time required for program
ACC
IL
) for at least “t
from the WP/ACC pin returns the device to normal operation. Do not remove V
IH
IL
on the WP/ACC pin, the device reverts to whether the two outermost 8 Kbyte on both
on the WP/ACC pin, the device disables program and erase functions in the two
RP
” in order to properly reset the internal state machine. Any operation in the process
IL
. The RESET pin has a pulse requirement and has to
MBM29DL640E
ACC
from WP/
READY
80/90/12
” after
RH
ID
”
.
27