This repository contains a Video Controller. This controller includes not only the low-level framer, but also a bus controller to read values from memory to then be displayed on the screen. This is the basis of a frame buffer approach to video.
This capability is fully demonstrated via the Verilator based simulator.
This repository also contains two basic video simulator components. The first takes video outputs from a Verilated design module and displays them on your screen as though it were the monitor the design was displaying to, and the second takes a piece of your screen and creates a VGA source signal with it.
All video modes are supported by simply creating the simulator object with the appropriate mode lines, although the memory initialization file for the outgoing demo is specifically formatted for a 1280x1024 screen. The simulator will then create a window of that size on any GTK enabled screen (i.e. Linux), displaying whatever image your design is producing.
The repository also contains a test pattern generator modeled roughly after a standard VGA pattern, although not quite the same. As mentioned above, there's also a frame buffered approach to drawing on the window centered around a wishbone enabled memory driver. This second capability will draw a more arbitrary image on the display.
References to VGA within this module could just as easily refer to any display. Be careful that you match the proper polarity of the sync pulses.
There is a master Makefile in this directory. Hence, to build
this project you should be able to just clone it,
git clone https://github.com/ZipCPU/vgasim, run make in the main
directory, and then run main_tb from within the bench/cpp directory.
The project does depend upon having both Verilator and gtkmm-3.0 installed.
All of the source code in this repository is released under the GPLv3. If these conditions are not sufficient for your needs, other licenses terms may be purchased.