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CHAPTER 8 8/16-BIT CAPTURE TIMERS/COUNTERS
8.1
Overview of 8/16-bit Capture Timer/Counter
The 8/16-bit capture timer/counter consists of two 8-bit counters (timer 0 and timer 1).
These counters can be used separately (8-bit mode) or in combination (16-bit mode).
Timer 0 provides seven internal count clocks. This time can select the interval timer
function or counter function. The interval timer function increments the counter value
in synchronization with one of the seven internal clocks. The counter function
increments the counter value according to the clock to be input to an external pin.
Timer 0 can output square waves of any frequency according to outputs from the
interval timer and counter.
Timer 1 provides seven internal count clocks. This timer can output square waves of
any frequency but can use only the interval timer function that increments the timer
value in synchronization with one of the seven internal counter clocks. For the 16-bit
mode, timer 0 and timer 1 are connected in series to serve as a 16-bit timer.
s Interval Timer Function
The interval timer function generates interrupt requests repeatedly at any time interval.
This function can also invert the output levels of P34, TO, and INT10 pins per time interval and
output square waves of any frequency.
In the 8-bit mode, the interval timer function operates as two independent timers (timer 0 (8-
bit capture timer/counter) and timer 1 (8-bit timer)). Interval timer operation from each count
clock cycle to a 28 times cycle is possible.
The interval timer function can select and output square waves to the TO pin according to
the timer 0 or 1 output.
In the 16-bit mode, the interval timer function operates as a 16-bit capture timer/counter in
which timer 0 is concatenated as the lower counter and timer 1 is concatenated as the upper
counter.
Interval timer operation from the count clock cycle to the 216 times cycle is
possible.
The count clock can be selected from the seven internal clock cycles (if timer 0 selects an
external clock, the interval timer function operates as the capture/counter function).
The timer 0 output cycle can be used as the clock for starting A/D converters continuously or
as the 8-bit PWM timer count clock.
3 "Interval Time and Square Wave Output Range in 16-bit Mode" show the interval time and