608
TCSR—Timer Control/Status Register
H'A8
WDT
Bit
Initial value
Read/Write
7
OVF
0
R/(W)
6
WT/
0
R/W
5
TME
0
R/W
4
—
1
—
3
—
1
—
0
CKS0
0
R/W
2
CKS2
0
R/W
1
CKS1
0
R/W
Overflow flag
Timer mode select
IT
0
[Clearing condition]
Read OVF when OVF = 1, then write 0 in OVF
1
[Setting condition]
TCNT changes from H'FF to H'00
0
Interval timer: requests interval timer interrupts
1
Watchdog timer: generates a reset signal
Clock select 2 to 0
0
1
ø/2
ø/32
ø/64
ø/128
ø/256
ø/512
ø/2048
0
1
0
1
0
1
0
1
0
1
0
ø/4096
1
Timer enable
0
1
TCNT is initialized to H'00 and halted
TCNT is counting
Note:
*
Only 0 can be written to clear the flag.
*
CKS2 CKS1 CKS0 Description