197
3.
Timer control register F (TCRF)
TCRF is an 8-bit write-only register that switches between 16-bit mode and 8-bit mode, selects the
input clock from among four internal clock sources or external event input, and sets the output
level of the TMOFH and TMOFL pins.
TCRF is initialized to H'00 upon reset.
Bit 7: Toggle output level H (TOLH)
Bit 7 sets the TMOFH pin output level. The output level is effective immediately after this bit is
written.
Bit 7
TOLH
Description
0
Low level
(initial value)
1
High level
Bits 6 to 4: Clock select H (CKSH2 to CKSH0)
Bits 6 to 4 select the clock input to TCFH from among four internal clock sources or TCFL
overflow.
Bit 6
Bit 5
Bit 4
CKSH2
CKSH1
CKSH0
Description
0
0
0
16-bit mode, counting on TCFL overflow signal
(initial value)
0
0
1
0
1
0
0
1
1
Use prohibited
1
0
0
Internal clock: counting on ø/32
1
0
1
Internal clock: counting on ø/16
1
1
0
Internal clock: counting on ø/4
1
1
1
Internal clock: counting on øw/4
*:
Don’t care
TOLH
CKSL2
CKSL1
CKSL0
CKSH2
CKSH1
CKSH0
TOLL
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
W
W
W
W
W
W
W
W
Bit:
Initial value:
Read/Write: