Sunday, 28 December 2014

USB-UART control port

As part of my GSoC assignment, I tried to expose the control port via uart, in addition to control port via usb which was already present. I could not get it to work that time. So now I took the job again. Instead on working on my previous code, I decided to start with a clean slate.
My approach was to mux the already available resource which was being used for usb control port. After many hours of understanding the simulation waveforms, I finally managed to get things working, umm partially.
There are two kinds of commands. One which cause some changes for example forcing output video to be in grayscale, changing to HDMI0 etc. These are currently working in my uart control port. Then there are commands which output status back to the terminal. Now these currently don't work and I can get them working. The only problem will be that then the tools/fpga_debug will have to be written again for uart which will be plenty of work to do before sprints starts.