M16C6K9 Datasheet, PDF (86/292 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6K9 Group
Timer A
Table.FB-3 Timer specifications in event counter mode (when processing two-phase pulse signals with timers A2, A3, and A4)
Item
Specification
Count source
• Two-phase pulse signals input to TAiIN and TAiOUT pin
Count operation
• Up count or down count can be selected by two-phase pulse signals
• 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
TAiIN pin function
Two-phase pulse input
TAiOUT pin function
Two-phase pulse input
Read from timer
Count value can be read out by reading timer A2, A3, or A4 register
Write to timer
• 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.)
Select function
• Normal processing operation
The timer up-counts by the rising edge of TAiIN pin and down-counts by the
falling edge fo TAiIN pin during the "H" level period of input signal in TAiOUT
pin.
TAiOUT
TAiIN
(i=2,3) Up
count
Up
count
Up Down
count count
Down
count
Down
count
• Multiply-by-4 processing operation
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
Note: This does not apply when the free-run function is selected.
Count down all edges
Rev.1.00 Jun 06, 2003 page 86 of 290