M16C65 Datasheet, PDF (336/829 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M16C/60

Under development
M16C/65 Group
Preliminary Specification
This is a preliminary specification and is subject to change.
17. Timer A
17.3 Operations
17.3.1 Common Operations
17.3.1.1 Operating Clock
The count source for each timer acts as a clock, controlling such timer operations as counting and
reloading.
If the conditions to start counting are met, the counter not operating starts counting at the count timing
of the first count source. For this reason, a delay exists between when the count start conditions are
met and the counter starts counting. Figure 17.4 shows Output Example of One-Shot Timer Mode.
Count source
TAiIN (trigger input)
TAiOUT
(one-shot pulse output)
Trigger input
Count start
= output start
Maximum 1.5 cycles of the count source
Figure 17.4 Output Example of One-Shot Timer Mode
17.3.1.2 Counter Reload Timing
Timer Ai starts counting from the value (n) set in the TAi register. The TAi register consists of a counter
and a reload register. The counter starts decrementing the count source from n, reloads a value in the
reload register at the next count source after the value becomes 0000h, and continues decrementing.
(When incrementing, the counter reloads a value in the reload register at the next count source after the
value becomes FFFFh.)
The value written in the TAi register is reflected in the counter and the reload register at the timings
below.
• When the count is stopped
• Between when the count starts and the first count source is input
A value written to the TAi register is immediately written to the counter and the reload register.
• After the count starts and the first count source is input
A value written to the TAi register is immediately written to the reload register. The counter
continues counting and reloads the value in the reload register at the next count source after the
value becomes 0000h (or FFFFh).
REJ09B0484-0030 Rev.0.30 Sep 09, 2008
Page 301 of 791