M16C62N Datasheet, PDF (76/213 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Timer A
Mitsubishi microcomputers
M16C / 62N Group (80-pin)
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Table 1.13.3. Timer specifications in event counter mode (when processing two-phase pulse signal with timers A2, A3, and A4)
Item
Count source
Count operation
Divide ratio
Count start condition
Count stop condition
Interrupt request generation timing
TAiIN pin function
TAiOUT pin function
Read from timer
Write to timer
Select function (Note 3)
Specification
• Two-phase pulse signals input to TAiIN or TAiOUT pin
• Up count or down count can be selected by two-phase pulse signal
• When the timer overflows or underflows, the reload register content is
reloaded and the timer starts over again (Note)
1/ (FFFF16 - n + 1) for up count
1/ (n + 1) for down count
n : Set value
Count start flag is set (= 1)
Count start flag is reset (= 0)
Timer overflows or underflows
Two-phase pulse input (Set the TAiIN pin correspondent port direction register to “0”)
Two-phase pulse input (Set the TAiOUT pin correspondent port direction register to “0”)
Count value can be read out by reading timer A2, A3, or A4 register
• When counting stopped
When a value is written to timer A2, A3, or A4 register, it is written to both
reload register and counter
• When counting in progress
When a value is written to timer A2, A3, or A4 register, it is written to only
reload register. (Transferred to counter at next reload time.)
• Normal processing operation (timer A2 and timer A3)
The timer counts up rising edges or counts down falling edges on the TAiIN
pin when input signal on the TAiOUT pin is “H”
TAiOUT
TAiIN
(i=2,3) Up
Up
Up Down Down Down
count count count count count count
• Multiply-by-4 processing operation (timer A3 and timer A4)
If the phase relationship is such that the TAiIN pin goes “H” when the input
signal on the TAiOUT pin is “H”, the timer counts up rising and falling edges
on the TAiOUT and TAiIN pins. If the phase relationship is such that the
TAiIN pin goes “L” when the input signal on the TAiOUT pin is “H”, the timer
counts down rising and falling edges on the TAiOUT and TAiIN pins.
TAiOUT
Count up all edges
TAiIN
(i=3,4)
Count down all edges
Count up all edges Count down all edges
Note 1: This does not apply when the free-run function is selected.
Note 2: Timer A1 and A2 do not have I/O port (TAiIN and TAiOUT).
Note 3: Timer A3 alone can be selected. Timer A2 is fixed to normal processing operation, and timer A4 is
fixed to multiply-by-4 processing operation.
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