Renesas M16C Series User Manual

Timer A
M30240 Group
Rev.1.00 Sep 24, 2003 Page 71 of 360
Table 1.20: Timer specification in event counter mode (when processing two-phase pulse signal with
Timers A2, A3, A4.)
Figure 1.65 shows Timer Ai mode register in event counter mode when processing two-phase signal.
Item Specification
Count Source •Two-phase pulse signals input to TAi
IN
or TAi
OUT
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 loaded and the timer starts over
again (Note 1)
Divide ratio
1/ (FFFF
16
- 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 overflow or underflows
TAi
IN pin function Two-phase pulse input
TAi
OUT pin function Two-phase pulse input
Read from timer Count value can be read out by reading timer A2, A3, or A4 register
Writer to timer
•When counting is stopped and a value is written to timer A2, A3, or A4 register, it is written to both the
reload register and counter
•When counting is in progress and a value is written to timer A2, A3, or A4 register, it is written to only
reload register to be transferred to counter at the next reload time.
Select function
•Normal processing operation
The timer counts up rising edges or counts down falling edges on the TAi
IN pin when input signal on
the TAi
OUT pin is “H”
•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 T
AiIN 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
TAiIN
(i=2,3)
Up
count
Up
count
Up
count
Down
count
Down
count
Down
count
Count up all edges Count down all edges
Count down all edgesCount up all edges
TAiOUT
TAiIN
(i=3,4)

Renesas M16C Series Specifications

General

Brand	Renesas
Model	M16C Series
Category	Computer Hardware
Language	English