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CHAPTER 5 Timebase timer
5.1
Overview of Timebase Timer
The timebase timer is an 18-bit free-run counter (timebase timer counter) that
increments in synchronization with the main clock (half frequency of main oscillation
clock).
• Four interval times can be selected and an interrupt request can be generated for
each interval time.
• An operation clock is supplied to the oscillation stabilization wait time timer and
other peripherals.
I Interval Timer Function
• When the timebase timer counter reaches the interval time set by the interval time select bits (TBTC:
TBC1, TBC0), an overflow occurs (TBTC: TBOF = 1) and an interrupt request is generated.
• When an interrupt is enabled when an overflow occurs (TBTC: TBIE = 1), an overflow occurs (TBTC:
TBOF = 1) and an interrupt is generated.
• The timebase timer has four interval times that can be selected.Table 5.1-1 shows the interval times of
the timebase timer.
Table 5.1-1 Interval Times of Timebase Timer
2/HCLK (0.5 µs)
HCLK: Oscillation clock
The parenthesized values are provided at 4-MHz oscillation clock.
192
Count Clock
Interval Time
12
2
/HCLK (approx. 1.0 ms)
14
2
/HCLK (approx. 4.1 ms)
16
2
/HCLK (approx. 16.4 ms)
19
2
/HCLK (approx. 131.1 ms)
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