Renesas M16C Series User Manual

Timer A
M30240 Group
Rev.1.00 Sep 24, 2003 Page 151 of 360
2.2.2.3 Timer Mode with Pulse-output Function Selected
In timer mode, select functions from those listed in Table 2.3 . An example using the indicated options
is described below. Figure 2.11 shows the operation timing, and Figure 2.12 shows the set-up proce-
dure.
Table 2.3: Timer A timer timing mode and pulse-output functions
Operation
(1) Setting the count start flag to “1” causes the counter to perform a down count on the count source.
(2) If an underflow occurs, the content of the reload register is reloaded and the count continues. At
this time, the Timer Ai interrupt request bit goes to “1”. Also, the output polarity of the TAiOUT pin re-
verses.
(3) Setting the count start flag to “0” causes the counter to hold its value and to stop. Also, the TAiOUT
pin outputs an “L” level.
Figure 2.11: Timer mode timing and pulse output function operation
Item
Set-up
Count source O Internal count source (f1/f8/f32)
Pulse output function
No pulses output
O Pulses output
Gate function
O No gate function
Performs count only for the period when the TAiIN pin is at “L”.
Performs count only for the period when the TAiIN pin is at “H”.
FFFF16
n
0000
16
Time
Count start flag
Timer Ai interrupt
request bit
“1”
“1”
Counter content (hex)
n = reload register content
Pulse output from
TA i
OUT pin
“H”
“0”
“L”
“0”
Set to “1” by software
Set to “1” by software
Cleared to “0” by
software
(3) Stop count
Cleared to “0” when interrupt request is accepted, or cleared by software
(1) Start count
(2) Underflow
Start count again

Renesas M16C Series Specifications

General

Brand	Renesas
Model	M16C Series
Category	Computer Hardware
Language	English