M58WR016KU Datasheet, PDF (39/123 Pages) STMicroelectronics – 16- or 32-Mbit (×16, Mux I/O, Multiple Bank, Burst) 1.8 V supply Flash memories

M58WRxxxKU, M58WRxxxKL
Status Register
7.3
Erase Status bit (SR5)
The Erase Status bit can be used to identify if the memory has failed to verify that the block
has erased correctly. When the Erase 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 Status bit should be read once the Program/Erase
Controller Status bit is High (Program/Erase Controller inactive).
Once set High, the Erase Status bit can only be reset Low by a Clear Status Register
command or a hardware reset. If set High it should be reset before a new Program or Erase
command is issued, otherwise the new command will appear to fail.
7.4
Program Status bit (SR4)
The Program Status bit is used to identify either a Program failure, or an attempt to program
a ‘1’ to an already programmed bit when V_PP = V_PPH.
When the Program Status bit goes High (set to ‘1’) after a Program failure, the
Program/Erase Controller has applied the maximum number of pulses to the byte and still
failed to verify that it has programmed correctly.
After an attempt to program a ‘1’ to an already programmed bit, the Program Status bit SR4
only goes High (set to ’1’) if V_PP = V_PPH (if V_PP ≠ V_PPH, SR4 remains Low (set to ‘0’) and the
attempt is not shown).
The Program Status bit should be read once the Program/Erase Controller Status bit is High
(Program/Erase Controller inactive).
Once set High, the Program Status bit can only be reset Low by a Clear Status Register
command or a hardware reset. If set High it should be reset before a new command is
issued, otherwise the new command will appear to fail.
7.5
V_PP Status bit (SR3)
The V_PP Status bit can be used to identify an invalid voltage on the V_PP pin during Program
and Erase operations. The V_PP pin is only sampled at the beginning of a Program or Erase
operation. Indeterminate results can occur if V_PP becomes invalid during an operation.
When the V_PP Status bit is Low (set to ‘0’), the voltage on the V_PP pin was sampled at a valid
voltage; when the V_PP Status bit is High (set to ‘1’), the V_PP pin has a voltage that is below
the V_PP Lockout Voltage, V_PPLK, the memory is protected and Program and Erase
operations cannot be performed.
Once set High, the V_PP Status bit can only be reset Low by a Clear Status Register
command or a hardware reset. If set High it should be reset before a new Program or Erase
command is issued, otherwise the new command will appear to fail.
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