Rev. 1.0, 02/00, page 1093 of 1141
H'FFBB: Timer Counter A TCA: TimerA
0
0
1
0
R
2
0
R
3
0
4
5
6
7
R
R
TCA3
0
R
TCA4
0
R
TCA5
0
R
TCA6
0
R
TCA7
TCA2
TCA1
TCA0
Bit :
Initial value :
R/W :
H'FFBC: Watchdog Timer Control/Status Register WTCSR: WDT
7
OVF
0
R/(W)*
6
WT/IT
0
R/W
5
TME
0
R/W
4
—
0
—
3
RST/NMI
0
R/W
0
CKS0
0
R/W
2
CKS2
0
R/W
1
CKS1
0
R/W
Note: * Only 0 can be written to clear the flag.
Overflow flag
WTCNT is initialized to H'00 and halted
(Initial value)
WTCNT counts
0
1
NMI interrupt request is generated
(Initial value)
Internal reset request is generated
0
1
Timer mode select bit
Timer enable bit
Reset or NMI
Interval timer mode: Sends the CPU an interval timer interrupt
request (WOVI) when WTCNT overflows
(Initial value)
Watchdog timer mode: Sends the CPU a reset or NMI interrupt
request when WTCNT overflows
0
1
[Clearing conditions]
(1) Write 0 in the TME bit
(Initial value)
(2) Read WTCSR when OVF = 1, then write 0 in OVF
[Setting conditions]
When WTCNT overflows (changes from H'FF to H'00)
(When internal reset request generation is selected in watchdog timer mode,
OVF is cleared automatically by the internal reset.)
0
1
Bit :
Initial value :
R/W :