29LV650 データシートの表示（PDF） - Fujitsu

部品番号

コンポーネント説明

メーカー

29LV650

FLASH MEMORY CMOS 64M (4M x 16) BIT

Fujitsu 

MBM29LV650UE/651UE-90/12

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” 32K word sector

without using VID.

If the system asserts VIL on the WP pin, the device disables program and erase functions in the “outermost”

32K word sector independently of whether this sector was protected or unprotected using the method described

in “Sector Protection/Unprotection”. The outermost 32K 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 32K 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 offers 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 50%. 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. Set

command to fast mode and reset command from fast mode is not necessary. 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

while programming. (See Figure 15.)

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