8-bit AVR Microcontroller

Compare Output Mode and Waveform Generation

The waveform generator uses the COM1x1:0 bits differently in normal, CTC, and PWM modes. For all modes, setting the COM1x1:0 = 0 tells the waveform generator that no action on the OC1x Register is to be performed on the next Compare Match. For compare output actions in the non-PWM modes refer to Table 1. For fast PWM mode refer to Table 2, and for phase correct and phase and frequency correct PWM refer to Table 3.

A change of the COM1x1:0 bits state will have effect at the first Compare Match after the bits are written. For nonPWM modes, the action can be forced to have immediate effect by using the FOC1x strobe bits.