M16C6S_09 Datasheet, PDF (85/208 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6S Group
Timer A
Table 1.12.3. Specifications in Event Counter Mode (when processing two-phase pulse signal with timer A4)
Item
Specification
Count source
• Two-phase pulse signals input to TAiIN or TAiOUT pins (i = 4)
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 con-
tents and continues counting. When operating in free-running mode, the
timer continues counting without reloading.
Divide ratio
1/ (FFFF16 - n + 1) for up-count
1/ (n + 1) for down-count n : set value of TAi register 000016 to FFFF16
Count start condition
Set TAiS bit of TABSR register to “1” (= start counting)
Count stop condition
Set TAiS bit to “0” (= stop counting)
Interrupt request generation timing Timer overflow or underflow
TAiIN pin function
Two-phase pulse input
TAiOUT pin function
Two-phase pulse input
Read from timer
Count value can be read by reading timer A4 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 reload register
(Transferred to counter when reloaded next)
Select function
• Multiply-by-4 processing operation (timer A4)
If the phase relationship is such that TAkIN(k=4) pin goes “H” when the input
signal on TAkOUT pin is “H”, the timer counts up rising and falling edges on
TAkOUT and TAkIN pins. If the phase relationship is such that TAkIN pin
goes “L” when the input signal on TAkOUT pin is “H”, the timer counts down
rising and falling edges on TAkOUT and TAkIN pins.
TAkOUT
Count up all edges
TAkIN
(k=3,4)
Count up all edges
Count down all edges
Count down all edges
Rev.5.01 Dec 10, 2009 page 85 of 201
REJ03B0014-0501