M16C30_02 Datasheet, PDF (83/178 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Timer A
Mitsubishi microcomputers
M16C / 30 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Table 1.14.3. Timer 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 pin
Count operation
• 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)
Divide ratio
1/ (FFFF16 - n + 1) for up count
1/ (n + 1) for down count
n : Set value
Count start condition
Count start flag is set (= 1)
Count stop condition
Count start flag is reset (= 0)
Interrupt request generation timing Timer overflows or underflows
TA2IN pin function
Two-phase pulse input (Set the TA2IN pin correspondent port direction register to “0”.)
TA2OUT pin function
Two-phase pulse input (Set the TA2OUT pin correspondent port direction register to “0”.)
Read from timer
Count value can be read out by reading timer A2 register
Write to timer
• When counting stopped
When a value is written to timer A2 register, it is written to both reload
register and counter
• When counting in progress
When a value is written to timer A2 register, it is written to only reload
register. (Transferred to counter at next reload time.)
Select function
• Normal processing operation
The timer counts up rising edges or counts down falling edges on the TA2IN
pin when input signal on the TA2OUT pin is “H”.
TA2OUT
TA2IN
Up
Up
Up Down Down Down
count count count count count count
Note: This does not apply when the free-run function is selected.
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