M16C30P_07 Datasheet, PDF (119/317 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/30 SERIES

M16C/30P Group
14. Timers
Table 14.3 lists Specifications in Event Counter Mode (when processing two-phase pulse signal with Timer A2).
Figure 14.10 shows TA2MR Register in Event Counter Mode (when using two-phase pulse signal processing with
Timer A2).
Table 14.3 Specifications in Event Counter Mode (when processing two-phase pulse signal with
Timer A2)
Item
Specification
Count Source
• Two-phase pulse signals input to TA2IN or TA2OUT pins
Count Operation
• Up-count or down-count can be selected by two-phase pulse signal
• When the timer overflows or underflows, it reloads the reload register contents
and continues counting. When operating in free-running mode, the timer
continues counting without reloading.
Divide Ratio
1/ (FFFFh - n + 1) for up-count
1/ (n + 1) for down-count n : set value of TA2 register 0000h to FFFFh
Count Start Condition Set TA2S bit of TABSR register to “1” (= start counting)
Count Stop Condition Set TA2S bit to “0” (= stop counting)
Interrupt Request
Generation Timing
Timer overflow or underflow
TA2IN Pin Function
Two-phase pulse input
TA2OUT Pin Function Two-phase pulse input
Read from Timer
Count value can be read by reading Timer A2 register
Write to Timer
• When not counting and until the 1st count source is input after counting start
Value written to TA2 register is written to both reload register and counter
• When counting (after 1st count source input)
Value written to TA2 register is written to reload register
(Transferred to counter when reloaded next)
Select Function
• The timer counts up rising edges or counts down falling edges on TA2IN pin
when input signals on TA2OUT pin is “H”.
TA2OUT
TA2IN
Up- Up-
Up- Down- Down- Down-
count count count count count count
Rev.1.22 Mar 29, 2007 Page 103 of 291
REJ09B0179-0122