r4f2456 Renesas Electronics Corporation., r4f2456 Datasheet - Page 853

• Manufacturer Part Number: r4f2456
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

14.6.2
If a timer counter clock pulse is generated during the next cycle after the T
cycle, the write takes priority and the timer counter is not incremented. Figure 14.5 shows this
operation.
14.6.3
If bits CKS2 to CKS0 in TCSR are written to while the WDT is operating, errors could occur in
the incrementation. Software must stop the watchdog timer (by clearing the TME bit to 0) before
changing the value of bits CKS2 to CKS0.
14.6.4
If the mode is switched from watchdog timer to interval timer, while the WDT is operating, errors
could occur in the incrementation. Software must stop the watchdog timer (by clearing the TME
bit to 0) before switching the mode.
φ
Address
Internal write signal
TCNT input clock
TCNT
Contention between Timer Counter (TCNT) Write and Increment
Changing Value of CKS2 to CKS0
Switching between Watchdog Timer Mode and Interval Timer Mode
Figure 14.5 Contention between TCNT Write and Increment
TCNT write cycle
T 1
T 2
Next cycle
N
Counter write data
Rev. 1.00 Sep. 19, 2008 Page 823 of 1342
Section 14 Watchdog Timer (WDT)
M
2
state of a TCNT write
REJ09B0467-0100