When reading from a GPIO pin, at what frequency do the crests and troughs of a wave begin to blend together to the point that the CPU can no longer distinguish between them?
I assume the answer depends on the CPU and implementation, so to keep this simple, let's assume I'm using a BeagleBone Black (because I am).
If I have a 1Ghz sine wave, ranging from 0V - 3.3V, will be BeagleBone Black still be able to read it as anything other than a blur of ~1.65V?
Edit: Ok, I'm not worried about 1GHz specifically. I'm just wondering at what frequency the GPIO pin can no longer discern between the crests and troughs of the wave. The 1GHz example was just meant to be an extreme case.