170
Timer Control Register F (TCRF)
Bit
7
6
5
4
3
2
1
0
TOLH
CKSH2
CKSH1
CKSH0
TOLL
CKSL2
CKSL1
CKSL0
Initial value
0
0
0
0
0
0
0
0
Read/Write
W
W
W
W
W
W
W
W
TCRF is an 8-bit write-only register. It is used to switch between 16-bit mode and 8-bit mode, to
select among four internal clocks and an external event, and to select the output level at pins
TMOFH and TMOFL.
Upon reset, TCRF is initialized to H'00.
Bit 7—Toggle Output Level H (TOLH): Bit 7 sets the output level at pin TMOFH. The setting
goes into effect 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 input to TCFH from four
internal clock signals or the overflow of TCFL.
Bit 6: CKSH2
Bit 5: CKSH1
Bit 4: CKSH0
Description
0
*
*
16-bit mode selected. TCFL overflow signals
are counted.
(initial value)
1
0
0
Internal clock: ø/32
1
Internal clock: ø/16
1
0
Internal clock: ø/4
1
Internal clock: ø/2
Note:
*
Don’t care
Bit 3—Toggle Output Level L (TOLL): Bit 3 sets the output level at pin TMOFL. The setting
goes into effect immediately after this bit is written.
Bit 3: TOLL
Description
0
Low level
(initial value)
1
High level