Toggle Bit 2 Flag (Dq2) - Fujitsu F2MC-8FX Hardware Manual

28.5.4

Toggle Bit 2 Flag (DQ2)

The toggle bit 2 flag (DQ2) is a hardware sequence flag used to indicate that chip-
erasing is executed using the toggle bit function.
Toggle Bit 2 Flag (DQ2)
Table 28.5-9 and Table 28.5-10 show the state transition of the toggle bit 2 flag.
Table 28.5-9 State Transition of Toggle Bit 2 Flag (During Normal Operation)
Operating state
Table 28.5-10 State Transition of Toggle Bit 2 Flag (During Abnormal Operation)
Operating state
*: When the DQ5 flag is 1 (execution time-out), the DQ2 flag toggles during continuous reading from the
programming/erasing sector but does not toggle during reading from other sectors.
At chip erasing
• When read access is made continuously during execution of the chip-erase algorithm, the flash memory
toggles the output between "1" and "0" at each read access.
• When read access is made continuously after the chip-erase algorithm is terminated, the flash memory
outputs bit 2 (DATA:2) of the value read from the read address at each read access.
Programming → Programming completed
DQ2
DQ2
CHAPTER 28 256-KBIT FLASH MEMORY
1 → DATA: 2
Programming
1
Chip erasing → Erasing completed
Toggle → Stop
Chip erasing
*
533