M58LT256JST datasheet(34/106 Pages) STMICROELECTRONICS

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Status Register

M58LT256JST, M58LT256JSB

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5.3

Erase/Blank Check Status bit (SR5)

The Erase/Blank Check Status bit is used to identify if there was an error during a Block

Erase operation. When the Erase/Blank Check Status bit is High (set to ‘1’), the

Program/Erase Controller has applied the maximum number of pulses to the block and still

failed to verify that it has erased correctly.

The Erase/Blank Check Status bit should be read once the Program/Erase Controller Status

bit is High (Program/Erase Controller inactive).

The Erase/Blank Check Status bit is also used to indicate whether an error occurred during

the Blank Check operation: if the data at one or more locations in the block where the Blank

Check command has been issued is different from FFFFh, SR5 is set to '1'.

Once set High, the Erase/Blank Check Status bit must be set Low by a Clear Status

the new command will appear to fail.

5.4

Program Status bit (SR4)

The Program Status bit is used to identify if there was an error during a program operation.

The Program Status bit should be read once the Program/Erase Controller Status bit is High

(Program/Erase Controller inactive).

When the Program Status bit is High (set to ‘1’), the Program/Erase Controller has applied

the maximum number of pulses to the word and still failed to verify that it has programmed

correctly.

Once set High, the Program Status bit must be set Low by a Clear Status Register

command or a hardware reset before a new program command is issued, otherwise the new

command will appear to fail.

5.5

VPP Status bit (SR3)

The VPP Status bit is used to identify an invalid voltage on the VPP pin during program and

erase operations. The VPP pin is only sampled at the beginning of a program or erase

operation. Program and erase operations are not guaranteed if VPP becomes invalid during

an operation.

When the VPP Status bit is Low (set to ‘0’), the voltage on the VPP pin was sampled at a valid

voltage.

When the VPP Status bit is High (set to ‘1’), the VPP pin has a voltage that is below the VPP

Lockout Voltage, VPPLK, the memory is protected and program and erase operations cannot

be performed.

Once set High, the VPP Status bit must be set Low by a Clear Status Register command or

a hardware reset before a new program or erase command is issued, otherwise the new

command will appear to fail.

M58LT256JST Datasheet(PDF) 34 Page - STMicroelectronics