Renesas M32R/ECU Series User Manual page 390

10
(3) Multiply-by-4 event count mode
In multiply-by-4 event count mode, the timer uses two external input signals in pairs (TIN24 and TIN25,
TIN26 and TIN27, or TIN28 and TIN29) as the clock sources for the counter. The count direction is switched
between up-count and down-count depending on the status of the two input signals.
By detecting the rising and falling edges on both of the two external input signals, the timer generates clock
pulses synchronized to the microcomputer's internal clock. When after setting the counter the timer is en-
abled (by writing to the enable bit in software), the counter starts counting synchronously with the generated
clock. To know whether the counter counts up or counts down, see Table 10.7.2 below.
An interrupt request can be generated when the counter underflows or overflows.
To stop the counter, disable count by writing to the enable bit in software or fix the external input signals
either "high" or "low".
Table 10.7.2 Count Direction during Multiply-by-4 Event Count Mode
Input
TIN24
H
(TIN26, TIN28)
TIN25
(TIN27, TIN29)
Count Direction
Up-count
L
H
10-147
MULTIJUNCTION TIMERS
10.7 TID (Input-Related 16-Bit Timer)
H
L
32180 Group User's Manual (Rev.1.0)
Down-count
L
L
H