Hitachi H8S/2378, H8S/2378R Series Hardware Manual page 654

Table 13.5 Switching of Internal Clock and TCNT Operation
Timing of Switchover
by Means of CKS1
No. and CKS0 Bits
1 Switching from
low to low*
2 Switching from
low to high*
3 Switching from
high to low*
Rev. 1.0, 09/01, page 610 of 904
TCNT Clock Operation
Clock before
1
switchover
Clock after
switchover
TCNT clock
TCNT
Clock before
2
switchover
Clock after
switchover
TCNT clock
TCNT
Clock before
3
switchover
Clock after
switchover
TCNT clock
TCNT
N N+1
CKS bit write
N N+1
CKS bit write
*
N N+1
CKS bit write
N+2
4
N+2