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Chapter 7 Timer/Counter Units
7
7.2 8-BIT TIMER/COUNTER 17.2.1 Functions

Eight-bit timer/counter 1 can function as an interval timer and can also be used for pulse width measurement. In

addition to these basic functions, 8-bit timer/counter 1 can be used as a timer for generating an output trigger on

a real-time output port.

(1) Interval timer

When operating as an interval timer, 8-bit timer/counter 1 generates an internal interrupt at specified intervals.

Table 7-9 Intervals of 8-Bit Timer/Counter 1

Resolution
16/fCLK
(2.6
µ
s)
32/fCLK
(5.3
µ
s)
64/fCLK
(10.7
µ
s)
128/fCLK
(21.3
µ
s)
256/fCLK
(42.7
µ
s)
512/fCLK
(85.3
µ
s)
Maximum interval
28 × 16/fCLK
(683
µ
s)
28 × 32/fCLK
(1.37 ms)
28 × 64/fCLK
(2.73 ms)
28 × 128/fCLK
(5.46 ms)
28 × 256/fCLK
(10.9 ms)
28 × 512/fCLK
(21.8 ms)
Minimum interval
16/fCLK
(2.6
µ
s)
32/fCLK
(5.3
µ
s)
64/fCLK
(10.7
µ
s)
128/fCLK
(21.3
µ
s)
256/fCLK
(42.7
µ
s)
512/fCLK
(85.3
µ
s)
The values in parentheses are based on fCLK = 6 MHz.

(2) Pulse width measurement

Eight-bit timer/counter 1 measures the pulse width of a signal applied to the external interrupt request input

pin INTP0.

Table 7-10 Pulse Width Measurement Range of 8-Bit Timer/Counter 1

Measurable pulse width
28 × 16/fCLK
(683
µ
s)
28 × 32/fCLK
(1.37 ms)
28 × 64/fCLK
(2.73
µ
s)
28 × 128/fCLK
(5.46 ms)
28 × 256/fCLK
(10.9 ms)
28 × 512/fCLK
(21.8 ms)
Resolution
16/fCLK
(2.6
µ
s)
32/fCLK
(5.3
µ
s)
64/fCLK
(10.7
µ
s)
128/fCLK
(21.3
µ
s)
256/fCLK
(42.7
µ
s)
512/fCLK
(85.3
µ
s)
The values in parentheses are based on fCLK = 6 MHz.