Maybe the following info is useful for builders who are using microcontrollers to control e.g. pulse timing:
i'm using the Parallax Propeller chip for some years now. I also use other platforms like Arduino or Raspberry Pi, but if i need exact timing i always use the Propeller.
It's not like a 'normal' microcontroller. It has 8 cores (called 'cogs') which are running completely parallel and more or less independent from each other at 80 MHz (although they can be synchronized through a 'hub'). Every cog has 2 timer/counter modules which also include a PLL. With these timer/counter modules it's possible to get high-resolution timing with down to 10 ns resolution, it's possible to generate frequencies with up to 9 digits resolution, and it's even possible to generate high-resolution video signals. Even such crazy things like a TV transmitter is possible, the only additional hardware needed is a short wire on a port pin acting as an antenna.
The chip costs about 8$ is available as DIL-40 or SMD version. You only need a 5 MHz crystal and a serial EEPROM to get it running. It has a built-in bootloader which loads the code from ext. EEPROM or from serial interface at every startup.
I highly recommend looking at the documentation:
Using it requires some different thinking if you have used 'normal' controllers in the past, but everything is logical and you will get good results very quick. Then you wonder how you could live without it in the past.
If you have any questions feel free to ask.