I am using Atmega1608, my scenario is I am giving a PWM using TCA module. Ton of PWM is 18us and Toff is 33uS. Now the question , is there any way in which I can force the output of PWM which is high to go low and upon arrival of a certain event and restart the PWM from that point? It sounds little confusing, but in general I want to force the Ton to go low and restart the PWM from CNT=0.
It depends how fast this needs to be.
With simpler timer PWM, you need a ping-ping swap between HW and SW control of the pin, typically under an interrupt.
Disable/enable of MCU peripherals usually allow access to clear/preset any registers, tho some also clear any prescalers to give a more determinate phase.
Those details are not always documented so you need to try a working system.
If you need sub-us instant shut off, like a current-fault signal, more advanced PWMs have fault inputs, but those usually simply trip the pin, they do not resync the timer.