MBM29F002TC Datasheet, PDF (20/46 Pages) Fujitsu Component Limited. – 2M (256K X 8) BIT

MBM29F002TC-55/-70/-90/MBM29F002BC-55/-70/-90
Data Protection
The MBM29F002TC/BC is designed to offer protection against accidental erasure or programming caused by
spurious system level signals that may exist during power transitions. During power up the device automatically
resets the internal state machine in the Read mode. Also, with its control register architecture, alteration of the
memory contents only occurs after successful completions of specific multi-bus cycle command sequences.
The device also incorporates several features to prevent inadvertent write cycles resulting from VCC power-up
and power-down transitions or system noise.
Low VCC Write Inhibit
To avoid initiation of a write cycle during VCC power-up and power-down, a write cycle is locked out for VCC less
than 3.2 V (typically 3.7 V). If VCC < VLKO, the command register is disabled and all internal program/erase circuits
are disabled. Under this condition the device will reset to the read mode. Subsequent writes will be ignored until
the VCC level is greater than VLKO. It is the users responsibility to ensure that the control pins are logically correct
to prevent unintentional writes when VCC is above 3.2 V.
Write Pulse “Glitch” Protection
Noise pulses of less than 5 ns (typical) on OE, CE, or WE will not initiate a write cycle.
Logical Inhibit
Writing is inhibited by holding any one of OE = VIL, CE = VIH or WE = VIH. To initiate a write cycle CE and WE
must be a logical zero while OE is a logical one.
Power-Up Write Inhibit
Power-up of the device with WE = CE = VIL and OE = VIH will not accept commands on the rising edge of WE.
The internal state machine is automatically reset to the read mode on power-up.
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