HD6417615 Hitachi Semiconductor, HD6417615 Datasheet - Page 558

• Manufacturer Part Number: HD6417615
• Description: Hardware Manual
• Manufacturer: Hitachi Semiconductor

13.4
13.4.1
If a count-up pulse is generated at the timing shown in figure 13.8 during a watchdog timer
counter (WTCNT) write cycle, the write takes priority and the timer counter is not incremented
(figure 13.8).
13.4.2
If the values of bits CKS2 to CKS0 are altered while the WDT is running, the count may
increment incorrectly. Always stop the watchdog timer (by clearing the TME bit to 0) before
changing the values of bits CKS2 to CKS0.
13.4.3
The WDT may not operate correctly if it is switched between watchdog timer mode and interval
timer mode while it is running.
To ensure correct operation, always stop the watchdog timer (by clearing the TME bit to 0) before
switching between watchdog timer mode and interval timer mode.
544
WTCNT input
Usage Notes
Contention between WTCNT Write and Increment
Changing CKS2 to CKS0 Bit Values
Switching between Watchdog Timer Mode and Interval Timer Mode
Internal write
Address
WTCNT
Figure 13.8 Contention between WTCNT Write and Increment
signal
clock
WTCNT address
N
Counter write data
M