Table of Contents
Advertisement
Table 9.1
Timer Functions (cont)
Name
Functions
•
Watchdog
Reset signal
timer
generated when8-
bit counter
overflows
•
Asynchro-
16-bit counter
nous
•
Also usable as two
event
independent 8-bit
counter
counters
•
Counts events
asynchronous to ø
and øw
9.2
Timer A
9.2.1
Overview
Timer A is an 8-bit timer with interval timing and real-time clock time-base functions. The clock
time-base function is available when a 32.768-kHz crystal oscillator is connected. A clock signal
divided from 32.768 kHz, from 38.4 kHz (if a 38.4 kHz crystal oscillator is connected), or from
the system clock, can be output at the TMOW pin.
1. Features
Features of timer A are given below.
• Choice of eight internal clock sources (ø/8192, ø/4096, ø/2048, ø/512, ø/256, ø/128, ø/32, ø/8).
• Choice of four overflow periods (1 s, 0.5 s, 0.25 s, 31.25 ms) when timer A is used as a clock
time base (using a 32.768 kHz crystal oscillator).
• An interrupt is requested when the counter overflows.
• Any of nine clock signals can be output at the TMOW pin: 32.768 kHz divided by 32, 16, 8, or
4 (1 kHz, 2 kHz, 4 kHz, 8 kHz) or 38.4 kHz divided by 32, 16, 8, or 4 (1.2 kHz, 2.4 kHz, 4.8
kHz, 9.6 kHz), and the system clock divided by 32, 16, 8, or 4.
• Use of module standby mode enables this module to be placed in standby mode independently
when not used.
176
Internal Clock
ø/8192
ø
/32
w
—
Event
Waveform
Input Pin
Output Pin Remarks
—
—
AEVL
—
AEVH
Advertisement
Table of Contents
