M16C28 Datasheet, PDF (129/423 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/Tiny SERIES

M16C/28 Group (M16C/28, M16C/28B)
12. Timer
12.1.3 One-shot Timer Mode
In one-shot timer mode, the timer is activated only once by one trigger. (See Table 12.4) When the
trigger occurs, the timer starts up and continues operating for a given period. Figure 12.11 shows the
TAiMR register in one-shot timer mode.
Table 12.4 Specifications in One-shot Timer Mode
Item
Specification
Count source
f1, f2, f8, f32, fC32
Count operation
• Decrement
• When the counter reaches 000016, it stops counting after reloading a new value
• If a trigger occurs when counting, the timer reloads a new count and restarts counting
Divide ratio
1/n n : set value of TAi register 000016 to FFFF16
Count start condition
However, the counter does not work if the divide-by-n value is set to 000016.
TAiS bit in the TABSR register is set to “1” (start counting) and one of the
following triggers occurs.
• External trigger input from the TAiIN pin
• Timer B2 overflow or underflow,
timer Aj (j=i-1, except j=4 if i=0) overflow or underflow,
timer Ak (k=i+1, except k=0 if i=4) overflow or underflow
• The TAiOS bit in the ONSF register is set to “1” (timer starts)
Count stop condition
• When the counter is reloaded after reaching “000016”
• TAiS bit is set to “0” (stop counting)
Interrupt request generation timing When the counter reaches “000016”
TAiIN pin function
I/O port or trigger input
TAiOUT pin function
I/O port or pulse output
Read from timer
An indeterminate value is read by reading TAi register
Write to timer
Select function
• When not counting and until the 1st count source is input after counting start
Value written to TAi register is written to both reload register and counter
• When counting (after 1st count source input)
Value written to TAi register is written to only reload register
(Transferred to counter when reloaded next)
• Pulse output function
The timer outputs a low when not counting and a high when counting.
Rev. 2.00 Jan. 31, 2007 ^{page 109} of 385
REJ09B0047-0200