HD6413008VF25 Datasheet, PDF (366/688 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

11. Watchdog Timer
11.4 Interrupts
During interval timer operation, an overflow generates an interval timer interrupt (WOVI). The
interval timer interrupt is requested whenever the OVF flag is set to 1 in TCSR.
11.5 Usage Notes
Contention between TCNT Write and Increment: If a timer counter clock pulse is generated
during the T₃ state of a write cycle to TCNT, the write takes priority and the timer count is not
incremented. See figure 11.8.
CPU: TCNT write cycle
T₁
T₂
T₃
φ
TCNT
Internal write
signal
TCNT input
clock
TCNT
N
M
Counter write data
Figure 11.8 Contention between TCNT Write and Count up
Changing CKS2 to CKS0 Bit: Halt TCNT by clearing the TME bit to 0 in TCSR before
changing the values of bits CKS2 to CKS0.
Rev.4.00 Aug. 20, 2007 Page 320 of 638
REJ09B0395-0400