2 articles were written in March 2016:

A while ago I ran across this video from w2aew where he explained using two generators and an integrator to form a stair-step generator. I was intrigued because it seemed like such a simple idea, and a useful one too, but I immediately thought of some improvements. First I wondered why he didn’t implement both generators with 555 timers, and second a voltage buffer on the output seems to be needed.

But then my mind wandered and I realized that the two oscillators were actually PWM generators. And then I it was only a small step to “this can be implemented in a PSoC much better”. So I went ahead and tried it.