M16C26A Datasheet, PDF (120/352 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/Tiny SERIES

M16C/26A Group (M16C/26A, M16C/26B, M16C/26T)
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 12.1.3.1.) When the
trigger occurs, the timer starts up and continues operating for a given period. Figure 12.1.3.1 shows the
TAiMR register in one-shot timer mode.
Table 12.1.3.1. Specifications in One-shot Timer Mode
Item
Specification
Count source
f1, f2, f8, f32, fC32
Count operation
• Down-count
• 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 Feb.15, 2007 page 103 of 329
REJ09B0202-0200