A special note on increasing performance. Since all PCA channel interrupts are all routed to one vector you will have a single ISR (interrupt service routine) for processing all of the output toggle interrupts from the PCA channels. It can be a good idea to loop inside the ISR and process all set bits of the PCA interrupt flag bits before exiting.

It is also possible to increase performance in some situations by limiting how many interrupts you will respond to. For example you could decide to respond to the channel 2 interrupt and use it to update the channel 1 next match value at the same time you are updating the channel 2 match value. In another example with synchronous edges on the output waveforms it can be useful to update two match registers at once simply because they will be set to the same match value.

Michael Karas


Michael Karas