Depending on the WAVSEL parameter in TC_CMR, the behavior of TC_CV varies.
With any selection, TC_RA, TC_RB and TC_RC can all be used as compare registers.
RA Compare is used to control the TIOAx output, RB Compare is used to control the TIOBx output (if correctly configured) and RC Compare is used to control TIOAx and/or TIOBx outputs.
Figure 1. Waveform Mode
