Rev. 1.0, 07/01, page 131 of 372
Section 10 Timer A
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 32.768kHz crystal oscillator is connected. Figure 10-1
shows a block diagram of timer A.
10.1 Features
•
Timer A can be used as an interval timer or a clock time base.
•
An interrupt is requested when the counter overflows.
•
Any of eight clock signals can be output from pin TMOW: 32.768 kHz divided by 32, 16, 8, or
4 (1 kHz, 2 kHz, 4 kHz, 8 kHz), or the system clock divided by 32, 16, 8, or 4.
Interval Timer
•
Choice of eight internal clock sources (
φ
/8192,
φ
/4096,
φ
/2048,
φ
/512,
φ
/256,
φ
/128,
φ
/32,
φ
8)
Clock Time Base
•
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).
TIM08A0A0000_000020010700