W19B160BT Datasheet, PDF (17/48 Pages) Winbond – 16Mbit, 2.7~3.6 volt CMOS flash memory

W19B160BT/B DATA SHEET
Then the system initially determines that the toggle bit is toggling and DQ5 has not gone high. The
system may continue to monitor the toggle bit and DQ5 through successive read cycles, and
determines the status as described in the previous paragraph. Alternatively, the system may choose
to perform other system tasks. In this case, the system must start at the beginning of the algorithm
while it returns to determine the status of the operation.
6.3.6 DQ3: Sector Erase Timer
After writing a sector erase 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 erase 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.
6.3.7 DQ5 : Exceeded Timing Limits
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.”
7. SPECIAL CHARACTERISTIC
The W19B160B provides a good performance in the wireless products. It is concerned with access
speed. If the access speed is quick to meet the demand of specification (70nS), the system’s
application is widely and performance is better than other low speed products.
- 17 -
Publication Release Date:Jan.04, 2008
Revision A5