TMP92CF30
2009-06-12
92CF30-241
3.12.2 Operation of Each Circuit
(1)
Prescaler
A 9-bit prescaler generates the input clock to TMRA01.The clock
φ
T0TMR is
selected using the prescaler clock selection register SYSCR0<PRCK>.
The prescaler operation can be controlled using TA01RUN<TA0PRUN> in the
timer control register. Setting <TA01PRUN> to “1” starts the count; setting
<TA01PRUN> to “0” clears the prescaler to “0” and stops operation. Table 3.12.2
shows the various prescaler output clock resolutions.
(Although the prescaler and the timer counter can be started separately, the
timer counter’s operation depends on the prescaler’s input timing.)
Table 3.12.2 Prescaler Output Clock Resolution
Timer counter input clock
Prescaler of TMRA
TAxxMOD<TAxCLK1:0>
Clock gear
selection
SYSCR1
<GEAR2:0>
Prescaler of
clock gear
SYSCR0
<PRCK>
−
φ
T1(1/2)
φ
T4(1/8)
φ
T16(1/32)
φ
T256(1/512)
000(1/1) fc/8
fc/32
fc/128
fc/2048
001(1/2) fc/16
fc/64
fc/256
fc/4096
010(1/4) fc/32
fc/128
fc/512
fc/8192
011(1/8) fc/64
fc/256
fc/1024
fc/16384
100(1/16)
0(1/2)
fc/128 fc/512 fc/2048
fc/32768
000(1/1) fc/32
fc/128
fc/512
fc/8192
001(1/2) fc/64
fc/256
fc/1024
fc/16384
010(1/4) fc/128
fc/512
fc/2048
fc/32768
011(1/8) fc/256
fc/1024
fc/4096
fc/65536
fc
100(1/16)
1(1/8)
1/2
fc/512 fc/2048 fc/8192
fc/131072
(2)
Up counters (UC0 and UC1)
These are 8-bit binary counters which count up the input clock pulses for the
clock specified by TA01MOD.
The input clock for UC0 is selectable and can be either the external clock input
via the TA0IN pin or one of the three internal clocks
φ
T1,
φ
T4 or
φ
T16. The clock
setting is specified by the value set in TA01MOD<TA01CLK1:0>.
The input clock for UC1 depends on the operation mode. In 16-bit timer mode,
the overflow output from UC0 is used as the input clock. In any mode other than
16-bit timer mode, the input clock is selectable and can either be one of the internal
clocks
φ
T1,
φ
T16 or
φ
T256, or the comparator output (The match detection signal)
from TMRA0.
For each interval timer the timer operation control register bits TA01RUN
<TA0RUN> and TA01RUN<TA1RUN> can be used to stop and clear the up
counters and to control their count. A reset clears both up counters, stopping the
timers.
Note: TMR45 and TMR67 can be selected low-frequency clock(fs) instead of external clock input.
Summary of Contents for TLCS-900/H1 Series
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