VSDSquadron FPGA mini Lab: Basic Message Display on RISC-V core

Prerequisites

Install the following tools before proceeding:

# General dependencies
sudo apt-get install git vim autoconf automake autotools-dev curl libmpc-dev \
libmpfr-dev libgmp-dev gawk build-essential bison flex texinfo gperf libtool \
patchutils bc zlib1g-dev libexpat1-dev gtkwave picocom -y

# FPGA toolchain (Yosys/NextPNR/IceStorm)
sudo apt-get install yosys nextpnr-ice40 icestorm iverilog -y

# RISC-V Toolchain (GCC 8.3.0)
cd ~
mkdir -p riscv_toolchain && cd riscv_toolchain
wget "https://static.dev.sifive.com/dev-tools/riscv64-unknown-elf-gcc-8.3.0-2019.08.0-x86_64-linux-ubuntu14.tar.gz"
tar -xvzf riscv64-unknown-elf-gcc-*.tar.gz
echo 'export PATH=$HOME/riscv_toolchain/riscv64-unknown-elf-gcc-8.3.0-2019.08.0-x86_64-linux-ubuntu14/bin:$PATH' >> ~/.bashrc
source ~/.bashrc

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Setup

1. Clone the repository:

   cd ~
   git clone https://github.com/vsdip/vsdfpga_labs

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Hardware Connections

Source Component	Source Pin/Port	Destination Component	Destination Pin/Port
CH340	TX	VSDFPGA Board	3
CH340	RXD	VSDFPGA Board	4
VSDFPGA Board	GND	FPGA Board	23
CH340	3.3V	CH340	VCC

• Connect the VSDSquadron FPGA mini board to one USB port.
• Connect the CH340 module to another USB port.

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Building & Flashing

1. Review the RISC-V logo code (do not modify):

   cd ~/vsdfpga_labs/basicRISCV/Firmware
   nano riscv_logo.c  # Review and close (Ctrl+X)
   make riscv_logo.bram.hex

You should see the below messages

2. Build the firmware and FPGA bitstream:

   cd ~/vsdfpga_labs/basicRISCV/RTL
   make clean
   make build

3. Flash to FPGA:

   sudo make flash

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Running the Lab

1. Open the serial terminal:

   make terminal

   Expected Output:
   You should see repeated messages containing RISC-V logo data (e.g., ASCII art patterns).

   

2. Press Ctrl+A → Ctrl+Q to exit picocom.

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Notes

1. If /dev/ttyUSB0 is unavailable, update PICO_DEVICE in the Makefile.
2. The RISC-V toolchain must be in your PATH (configured in prerequisites).
3. Ensure all hardware connections match the table above for UART communication.