W19B320ATB Datasheet, PDF (18/53 Pages) Winbond – 4M × 8/2M × 16 BITS 3V FLEXIBLE BANK FLASH MEMORY

W19B320AT/B
DQ5 indicates whether the program or erase time has exceeded a specified internal pulse count limit.
DQ5 produces “1” under these conditions which indicates that the program or erase cycle was not
successfully completed.
The device may output “1” on DQ5 if the system tries to program “1” to a location that was previously
programmed to “0.” Only the erase operation can change “0” back to “1.” Under this condition, the device
stops the operation, and while the timing limit has been exceeded, DQ5 produces “1.”
Under both these conditions, the system must write the reset command to return to the read mode (or to the
erase-suspend-read mode if a bank was previously in the erase-suspend-program mode).
6.3.7 DQ3: Sector Erase Timer
After writing a sector erasure command sequence, the system may read DQ3 to determine whether erasure
has begun or not. (The sector erase timer does not apply to the chip erase command.) The entire time-out
applies after each additional sector erasure command if additional sectors are selected for erasure. Once
the timeout period has completed, DQ3 switches from “0” to “1.” If the time between additional sector erase
commands from the system can be assumed to be less than 50 μs, the system need not monitor, DQ3 does
not need to be monitored. Please also refer to Sector Erase Command Sequence section.
After the sector erase command is written, the system should read the status of DQ7 (#Data Polling) or
DQ6 (Toggle Bit I) to ensure that the device has accepted the command sequence, and then read DQ3. If
DQ3 is“1,” the Embedded Erase algorithm has begun; all further commands (except Erase Suspend) are
ignored until the erase operation is complete. If DQ3 is “0,” the device will accept additional sector erase
commands.
The system software should check the status of DQ3 before and following each subsequent sector erase
command to ensure the command has been accepted. If DQ3 is high on the second status check, the last
command might not have been accepted.
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