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9. Timers
Timer Control Register F (TCRF)
Bit
TOLH
Initial value
Read/Write
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 clock, 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
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
0
*
1
0
1
Legend: * 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
1
High level
Rev.3.00 Jul. 19, 2007 page 232 of 532
REJ09B0397-0300
7
6
5
CKSH2
CKSH1
0
0
0
W
W
W
Bit 4: CKSH0
*
0
1
0
1
4
3
CKSH0
TOLL
CKSL2
0
0
W
W
Description
16-bit mode selected. TCFL overflow signals
are counted
Internal clock: φ/32
Internal clock: φ/16
Internal clock: φ/4
Internal clock: φ/2
2
1
0
CKSL1
CKSL0
0
0
0
W
W
W
(initial value)
(initial value)
(initial value)
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