M32C8A Datasheet, PDF (178/372 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M32C/80 Series

M32C/8A Group
15. Timers (Timer A)
15.1.3 One-Shot Timer Mode
When a trigger occurs, the counter decrements until underflows. Then, the counter is reloaded and stops until
the next trigger occurs.
Table 15.6 lists specifications of one-shot timer mode. Figure 15.18 shows a one-shot timer mode operation.
Table 15.6 Specifications of One-Shot Timer Mode
Item
Count source
f1, f8, f2n⁽¹⁾, fC32
Specification
Count operation
• Counter decrements
When the counter reaches 0000h, the counter is reloaded and stops until the
next trigger occurs.
If a trigger occurs while counting, the contents of the reload register are
reloaded into the counter and the count continues.
Number of counting
n times n: setting value of the TAi register (i = 0 to 4), 0000h to FFFFh
(but the counter does not run if n = 0000h)
Count start condition
A trigger, selectable from the following, occurs while the TAiS bit in the TABSR
register is set to 1 (count starts):
• the TAiOS bit in the ONSF register is set to 1 (timer starts)
• an external trigger is applied to TAiIN pin
• timer B2 overflows or underflows,
• timer Aj overflows or underflows (j = i - 1, except j = 4 if i = 0),
• timer Ak overflows or underflows (k = i + 1, except k = 0 if i = 4)
Count stop condition
• After the counter reaches 0000h and the counter value is reloaded
• When the TAiS bit is set to 0 (count stops)
Interrupt request generation timing When the counter reaches 0000h
TAiIN pin function
Trigger input
TAiOUT pin function
Pulse output
Read from timer
A read from the TAi register returns undefined value
Write to timer
• A write to the TAi register while the count is stopped:
The value is written to both the reload register and the counter.
• A write to the TAi register while counting:
The value is written to the reload register (It is transferred to the counter at the
next reload timing).⁽²⁾
Selectable function
Pulse output function
“L” is output while the count stops. “H” is output while counting.
NOTES:
1. Bits CNT3 to CNT0 in the TCSPR register select no division (n = 0) or divide-by-2n (n = 1 to 15).
2. Wait for one count source cycle or more to write after the count starts.
Rev.1.00 Jul 15, 2007 Page 161 of 352
REJ09B0385-0100