By default, the TCB is in Periodic Interrupt mode. Follow these steps to start
using it:
- 1.Write a TOP value to the
Compare/Capture (TCBn.CCMP) register.
- 2.Optional: Write the Compare/Capture Output Enable (CCMPEN) bit in the Control B
(TCBn.CTRLB) register to ‘
1’. This will make the waveform output
available on the corresponding pin, overriding the value in the corresponding PORT
output register. The corresponding pin direction must be configured as an output in
the PORT peripheral.
- 3.Enable the counter by writing a
‘
1’ to the ENABLE bit in the Control A (TCBn.CTRLA) register. The counter will start counting clock ticks according to the
prescaler setting in the Clock Select (CLKSEL) bit field in the Control A
(TCBn.CTRLA) register.
- 4.The counter value can be read from
the Count (TCBn.CNT) register. The peripheral will generate a CAPT interrupt and
event when the CNT value reaches TOP.
- a.If the Compare/Capture register
is modified to a value lower than the current CNT, the peripheral will count to
MAX and wrap around.
- b.At MAX, an OVF interrupt and
event will be generated.