3. Timer control register F (TCRF)
Bit:
7
6
CKSH2
0
5
CKSH1
0
4
CKSH0
0
3
TOLL
0
2
CKSL2
0
1
CKSL1
0
0
CKSL0
0
TOLH
Initial value:
Read/Write:
0
W
W
W
W
W
W
W
W
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
Low level
0
1
(initial value)
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
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
16-bit mode, counting on TCFL overflow signal
(initial value)
Not available
Internal clock: counting on ø/32
Internal clock: counting on ø/16
Internal clock: counting on ø/4
Internal clock: counting on øw/4
*: Don't care
202
ETC [ ETC ]
