TH50VSF3680 Datasheet, PDF (34/55 Pages) Toshiba Semiconductor – SRAM AND FLASH MEMORY MIXED MULTI-CHIP PACKAGE

TH50VSF3680/3681AASB
HARDWARE SEQUENCE FLAGS FOR FLASH MEMORY
The TH50VSF3680/3681AASB has a Hardware Sequence flag which allows the device status to be determined
during an auto mode operation. The output data is read out using the same timing as that used when CEF = OE
= VIL in Read Mode. The RY/BY output can be either High or Low.
The device re-enters Read Mode automatically after an auto mode operation has been completed successfully. The
Hardware Sequence flag is read to determine the device status and the result of the operation is verified by
comparing the read-out data with the original data.
DQ7 (DATA polling)
During an Auto-Program or auto-erase operation, the device status can be determined using the data polling
function. DATA polling begins on the rising edge of WE in the last bus cycle. In an Auto-Program operation,
DQ7 outputs inverted data during the programming operation and outputs actual data after programming has
finished. In an auto-erase operation, DQ7 outputs 0 during the erase operation and 1 when the erase operation
has finished. If an auto mode operation fails, DQ7 simply outputs the data.
When the operation has finished, the address latch is reset. Data polling is asynchronous with the OE signal.
DQ6 (Toggle bit 1)
The device status can be determined by the Toggle Bit function during an Auto Program or Auto Erase
operation. The Toggle bit begins toggling on the rising edge of WE in the last bus cycle. DQ6 alternately
outputs a 0 or a 1 for each attempt ( OE access) while CEF = VIL while the device is busy. When the internal
operation has been completed, toggling stops and valid memory cell data can be read by subsequent reading. If
the operation failed, the DQ6 output toggles.
DQ6 toggles for around 3 µs when an attempt is made to execute an Auto Program operation on a protected
block. It then stops toggling. DQ6 toggles for around 100 µs when an attempt is made to execute an Auto Erase
operation on a protected block. It then stops toggling. After toggling stops the device returns to Read mode.
DQ5 (internal time-out)
DQ5 outputs a 1 when the Internal Timer has timed out during a Program or Erase operation. This indicates
that the operation has not completed within the allotted time.
An attempt to program 1 into a cell containing 0 will fail (see Auto Program mode). DQ5 outputs 1 in this case.
Either a hardware reset or a software reset command is required to put the device into Read mode.
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