M30245_06 RENESAS [Renesas Technology Corp], M30245_06 Datasheet - Page 15

• Manufacturer Part Number: M30245_06
• Description: RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/20 SERIES
• Manufacturer: RENESAS [Renesas Technology Corp]

M30245 Group
Rev.2.00 Oct 16, 2006
REJ09B0340-0200
2.2 Timer A
2.2.1 Overview
The following is an overview for timer A, a 16-bit timer.
(1) Mode
(2) Count source
Timer A operates in one of the four modes:
(a) Timer mode
(b) Event counter mode
(c) One-shot timer mode
(d) Pulse width modulation (PWM) mode
The internal count source can be selected from f
dividing the CPU's main clock by 1, 8, and 32 respectively. Clock f
secondary clock by 32.
In this mode, the internal count source is counted. Two functions can be selected: the pulse output
function that reverses output from a port every time an overflow occurs, or the gate function which
controls the count start/stop according to the input signal from a port.
This mode counts the pulses from the outside and the number of overflows in other timers. The free-
run type, in which nothing is reloaded from the reload register, can be selected when an underflow
occurs. The pulse output function can also be selected. Please refer to the timer mode explanation
for details, as the operation is identical.
Furthermore, Timer A has a two-phase pulse signal processing function which generates an up
count or down count in the event counter mode, depending on the phase of the two input signals.
The normal mode or 4-multiplication mode can be selected depending on the phase detective
method.
In this mode, the timer is started by the trigger and stops when the timer goes to “0”. The trigger can
be selected from the following 2 types: an overflow of the timer, or a software trigger. The pulse
output function can also be selected. Please refer to the timer mode explanation for details, as the
operation is identical.
In this mode, the arbitrary pulses are successively output. Either a 16-bit fixed-period PWM mode or
8-bit variable-period mode can be selected. The trigger for initiating output can also be selected.
Please refer to the one-shot timer mode explanation for details, as the operation is identical.
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1
, f
8
, f
32
, and f
C32
. Clocks f
C32
is derived by dividing the CPU's
1
, f
8
, and f
32
are derived by
2. Timer A