Getting back to trying this out finally.

So, I am converting a DC/DC converter that uses a very basic method of current control. I read the ADC value and compare it to the target ADC. If its below, I add +1 to the output HPWM, if its above the target ADC value I -1 to the HPWM value. This works ok if there are no upsets to input voltage or any rapid current changes on the output. It will oscillate quite badly on random occasions too. I think that is ripple on the ADC pin.

So I have just tried this for the first time and I'm getting some very unstable results. It is flickering quite badly. I'm sure this is a matter of tuning. Do you have any advice?
If I turn up the input voltage I also get to a point where it will no longer back off the output and try to maintain the correct current level, I assume this is a symptom of running into the lower level of the clamp?