Building a RISC-V computer on an Arty A7-35T FPGA board with SaxonSoc

We built a RISC-V computer running the X Window System (X11) and using the SaxonSoc on an Arty A7-35T FPGA board from Digilent.
We used a USB keyboard and a USB mouse, as shown in the xterm at the top left of the featured image.
This computer is based on github.com/SpinalHDL/SaxonSoc and github.com/SpinalHDL/buildroot-spinal-saxon.

SaxonSoc

The SaxonSoc is an SoC being developed by Charles Papon, the developer of the VexRiscv, and contributors.
Of course, the Soft CPU used in the SaxonSoc is the VexRiscv, a 32-bit RISC-V.
In the dev-0.3 branch currently under development, the supported FPGA boards are Radiona ULX3S, Digilent’s Arty A7 and Nexys A7.

RISC-V computer

We built a RISC-V computer with the following configuration.

• RISC-V single board computer
  • Digilent Arty A7-35T
  • Alternative to Pmod usb_host_x4
    • USB connector to DIP adapter x 2
    • Breadboard, jumper wires
  • Digilent Pmod VGA
  • Digilent Pmod MicroSD
• USB keyboard & mouse
• VGA display
• MicroSD
• USB cable (power supply & USB-UART)

The main specifications of the RISC-V computer based on the Arty A7-35T are as follows.

• CPU: Dual-core 32-bit RISC-V
  • ISA: RV32IMAFDC + AES custom extension
  • Operating frequency: 100 MHz
• DRAM: 256 MB
• Ethernet: 100 Mbps
• USB: 2 ports
• Display resolution: 1024×768
• Storage
  • Onboard Flash: for OpenSBI & U-Boot
  • MicroSD: for Linux & rootfs

Summary

We built a RISC-V computer running the X Window System (X11) on an Arty A7-35T with the SaxonSoc.
The feature of this computer is that we can use a USB keyboard and a USB mouse.
We think it’s good to be able to use the Window Maker as a window manager.