In complementary PWM mode, TCNT3 and TCNT4 overshoot and undershoot at the transitions
between up-counting and down-counting. The setting conditions for the IMFA bit in channel 3 and
the OVF bit in channel 4 differ from the usual conditions. In buffered operation the buffer transfer
conditions also differ. Timing diagrams are shown in figures 8-37 and 8-38.
TCNT3
GRA3
IMFA
Buffer transfer
signal (BR to GR)
GR
250
N – 1
N
Set to 1
Buffer transfer
Figure 8-37 Overshoot Timing
N + 1
N
N
N – 1
Flag not set
No buffer transfer