RISC-V-FPGA

RISC-V CPU for OpenFPGAs, in Icestudio

Quick start

• Open the soc-demo.ice file with Icestudio 12 or higher
• Connect the Alhambra-II board (or compatible) and upload the design
• It will take around 1 min to sinthesize and upload to the board
• The system is ready for executing your firmware!

Testing the firmaware in C

• go to the firmware/soc-demo/src-c folder
• Execute make (It is assumed that you already have the risc-v tools installed)
• You should see a binary counter in the LEDs
• If you open a serial terminal (115200 bauds) you will see messages

• In this youtube video you can see it in action!

• Pressing the "1" key will reset the counter and show the intial message again

Testing the firmware in asm

• go to the firmware/soc-demo/src-asm folder
• Execute make
• You should see a value in the LEDs

Credits

It is based on the picorv32 by Clifford Wolf https://github.com/cliffordwolf/picorv32

SOCs for the RARs simulator

There are two socs for using with the RARs simulador:

• soc-rars-MMIO-1-port.ice: It have no uart and 1 output port at address 0xFFFF0000, connected to the LEDs
• soc-rars-MMIO-2-ports.ice: The previous soc plus one additional output port, connected to the D0-D7 pins in the Alhambra II board

In the firmware/soc-rars-MMIO-1/rars and firmware/soc-rars-MMIO-2/rars folderS there are examples for trying. Open them with the RARs simulator, assemble and dump the code into a .bin file. Then flash it into the FPGA with iceprog tool:

iceprog -o 1M file.bin

or apio:

apio raw "iceprog -o 1M file.bin"