Waveform Output by Compare Match: In ITU channels 0, 1, 3, and 4, compare match A or B
can cause the output at the TIOCA or TIOCB pin to go to 0, go to 1, or toggle. In channel 2 the
output can only go to 0 or go to 1.
•
Sample setup procedure for waveform output by compare match
Figure 10-19 shows a sample procedure for setting up waveform output by compare match.
Figure 10-19 Setup Procedure for Waveform Output by Compare Match (Example)
•
Examples of waveform output
Figure 10-20 shows examples of 0 and 1 output. TCNT operates as a free-running counter, 0
output is selected for compare match A, and 1 output is selected for compare match B. When
the pin is already at the selected output level, the pin level does not change.
Output setup
Select waveform
output mode
Set output timing
Start counter
Waveform output
Select the compare match output mode (0, 1, or
toggle) in TIOR. When a waveform output mode
is selected, the pin switches from its generic input/
output function to the output compare function
(TIOCA or TIOCB). An output compare pin outputs
Set a value in GRA or GRB to designate the
compare match timing.
Set the STR bit to 1 in TSTR to start the timer
counter.
1
2
3
0 until the first compare match occurs.
1.
2.
3.
341
www.DataSheet4U.com