Pure Digital¶

A System On Chip which avoids using analog components, so that it can be synthesized using portable open source standard cell libraries like MOSIS or the output of the LibrePDK standard cell generator.

GPU¶

Here's a GPU
https://opencores.org/projects/gpu

Graphics output: DVI-D¶

We might be running into some problems even with DVI-D, without some additional smart circuiting, which can be seen in this project which tries to produce graphics output using a PicoRV32:
https://github.com/mattvenn/fpga-dvid-ice

We will need to provide some of those in order to have differential line pairs:
https://rocelec.widen.net/view/pdf/z7q6pesxyo/FAIRS14714-1.pdf

RAM bus: HyperRAM¶

We can use this controller here, in order to control HyperRAM:
https://github.com/gtjennings1/HyperBUS

They've made working boards using the PicoRV32