M16C30P_07 Datasheet, PDF (115/317 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/30 SERIES

M16C/30P Group
14. Timers
14.1.1 Timer Mode
In timer mode, the timer counts a count source generated internally (see Table 14.1). Figure 14.8 shows TAiMR
Register in Timer Mode.
Table 14.1 Specifications in Timer Mode
Item
Specification
Count source
f1, f2, f8, f32, fC32
Count Operation
• Down-count
• When the timer underflows, it reloads the reload register contents and
continues counting
Divide Ratio
1/(n+1) n: set value of TAi register (i= 0 to 2) 0000h to FFFFh
Count Start Condition Set TAiS bit in TABSR register to “1” (= start counting)
Count Stop Condition Set TAiS bit to “0” (= stop counting)
Interrupt Request
Generation Timing
Timer underflow
TAiIN Pin Function
I/O port or gate input
TAiOUT Pin Function I/O port or pulse output
Read from Timer
Count value can be read by reading TAi register
Write to Timer
• 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)
Select Function
• Gate function
Counting can be started and stopped by an input signal to TAiIN pin
• Pulse output function
Whenever the timer underflows, the output polarity of TAiOUT pin is inverted.
When TAiS bit is set to “0” (stop counting), the pin outputs a low.
Rev.1.22 Mar 29, 2007 Page 99 of 291
REJ09B0179-0122