Overview Of Timebase Timer - Fujitsu F2MC-8FX Hardware Manual

CHAPTER 10 TIMEBASE TIMER
10.1

Overview of Timebase Timer

The timebase timer is a 22-bit free-run down-counting counter which is synchronized
with the main clock divided by two. The timebase timer has an interval timer function
which can repeatedly generate interrupt requests at regular intervals.
Interval Timer Function
The interval timer function repeatedly generates interrupt requests at regular intervals by using the main
clock divided by two as the count clock.
• The counter of the timebase timer counts down so that an interrupt request is generated every time the
selected interval time elapses.
• The interval time can be selected from the following four types.
Table 10.1-1 shows the interval times available to the timebase timer.
Table 10.1-1 Interval Times of Timebase Timer
F : Main source oscillation clock
CH
The values in parentheses represent the values used when the main clock operates at 4MHz.
156
Internal count clock cycle
(0.5 μs)
2/F
CH
Interval time
10 (512.0 μs)
2 x 2/F
CH
12
2 x 2/F (2.05ms)
CH
14
2 x 2/F (8.19ms)
CH
16
2 x 2/F (32.77ms)
CH