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MBM29LV650UE90/651UE90
19
RESET
Hardware Reset Pin
The MBM29LV650UE/651UE devices may be reset by driving the RESET pin to VIL. The RESET pin has a pulse
requirement and has to be kept low (VIL) for at least “tRP” in order to properly reset the internal state machine.
Any operation in the process of being executed will be terminated and the internal state machine will be reset
to the read mode “tREADY” after the RESET pin is driven low. Furthermore, once the RESET pin goes high, the
devices require an additional “tRH” before it will allow read access. When the RESET pin is low, the devices 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.
Write Protect (WP)
The Write Protection function provides a hardware method of protecting certain “outermost” 32 K word sector
without using VID.
If the system asserts VIL on the WP pin, the device disables program and erase functions in the “outermost”
32 K word sector independently of the protection status of this sector. The outermost 32 K word sector is the
highest addresses in MBM29LV650UE, or the lowest addresses in MBM29LV651UE.
(MBM29LV650UE: SA127, MBM29LV651UE: SA0)
If the system asserts VIH on the WP pin, the device reverts to whether the outermost 32 K word sector was last
set to be protected or unprotected. That is, sector protection or unprotection for this sector depends on whether
this was last protected or unprotected using the method described in “Sector protection/unprotection”.
Accelerated Program Operation
MBM29LV650UE/651UE offer accelerated program operation which enables the programming in high speed. If
the system asserts VACC to the ACC pin, the device automatically enters the acceleration mode and the time
required for program operation will reduce to about 60%. This function is primarily intended to allow high speed
program, 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. It is
unnecessary to set command to fast mode and to reset command from fast mode. When the device enters the
acceleration mode, the device automatically set to fast mode. Therefore, the present sequence could be used
for programming and detection of completion during acceleration mode.
Removing VACC from the ACC pin returns the device to normal operation. Do not remove VACC from the ACC pin
during programming. Erase operation during Accelerated Program Operation is strictly prohibited.