Timing Limit Exceeding Flag (Dq5); Table 25-9 State Transition Of Timing Limit Exceeding Flag (State Change At Normal Operation); Table 25-10 State Transition Of Timing Limit Exceeding Flag (State Change At Abnormal Operation) - Fujitsu MB90420/5 (A) Series Hardware Manual

MB90420/5 (A) SERIES F

25.6.3 Timing Limit Exceeding Flag (DQ5)

The timing limit exceeding flag (DQ5) is used to notify that the automatic algorithm has executed beyond the
time (internal pulse count) specified in flash memory.
n Timing limit exceeding flag (DQ5)
Tables 25-9 and 25-10 gives the state transition of the timing limit exceeding flag.

Table 25-9 State Transition of Timing Limit Exceeding Flag (State change at normal operation)

Operating Programming
→ → Completed
State
0 → DATA:5
DQ5

Table 25-10 State Transition of Timing Limit Exceeding Flag (State change at abnormal operation)

Operating State
n At programming, chip sector erasing
When read access is performed after starting the automatic programming algorithm or the automatic chip
sector erasing algorithm, 0 is output when the time required for programming/erasing is within the specified
time; 1 is output when the time required for programming/erasing exceeds the specified time. Since this is
irrelevant to whether the automatic algorithm is currently being executed or is complete, this can be used to
determine whether programming/erasing succeeds or fails. In other words, when the automatic algorithm is
still being executed by the data polling function or toggle bit function with 1 output by this flag, it can be
detected that the programming fails.
For example, when writing 1 is sttempted into an address of the flash memory with 1 written, programming
fails. In this case, the flash memory will be locked and the automatic algorithm will not complete. Therefore,
no valid data is output from the data polling flag (DQ7). Also, the toggle bit flag (DQ6) does not stop the
toggle operation and exceeds the time limit, causing the timing limit exceeding flag (DQ5) to output 1. This
state indicates that the flash memory is not being used correctly; it does not indicate that the flash memory is
faulty. When this state occurs, execute the reset command.
2
MC-16LX FAMILY 16-BIT MICROCONTROLLERS HARDWARE MANUAL
Wait for
Chip Sector
Sector
Erasing
Erasing
→ → Completed
→ → Started
0 → 1
Programming
DQ5 1
Sector Erasing
Suspend
→ → Resumed
Sector being
Erased
0 0
Chip and Sector Erasing
25-14
Sector Erasing Sector Erasing
Suspended
→ → Resume
Suspended
Sector being Sector not Being
Erased
0
1
being
Erased
DATA:5