CNL_RISC-V - MC2101

MC2101is the first microcontroller implementation inside the CNL_RISC-V project, it is an open-source single-core microcontroller system based on a 32-bit RV32IM RISC-V core named AFTAB.

AFTAB is an in-order, single-issue core with sequential stages and it has full support for the base integer instruction set (RV32I) and multiplication instruction set extension (RV32M). It implements a subset of the 1.9 privileged specification. Further informations can be found in AFTAB's repo: https://github.com/RHESGroup/aftab

For the communication with the outside world MC2101 contains at the moment two peripherals:

• GPIO peripheral used to drive buttons, switches, leds and I/O pins on a board
• UART peripheral used by scanf and printf functions

MC2101 contains all the necessary to perform RTL simulations as well as FPGA synthesis

Repository folder structure

├── docs
│   ├── MC2101 User Manual.pdf
├── hw
│   ├── gpio
│   ├── include
│   ├── ssram
│   ├── uart
│   ├── core_bus_wrap.vhd
│   ├── mc2101.vhd
├── sw
│   ├── apps
│   ├── build
│   ├── libs
│   ├── ref
│   ├── utils
│   ├── cmake_configure.aftab.gcc.sh
│   ├── CMakeLists.txt
│   ├── README.md
│── target
│   ├── intel
│   ├── sim
│   ├── xilinx
├── util
├── env-riscv32.sh
├── Bender.lock
├── Bender.yml
└── README.md

Requirements

• VIVADO >= 2023.1
• RISC-V toolchain >= 13.2.0
• BENDER >= 0.28.1

1. Install RISC-V toolchain:

First, clone the suite of open source GNU tools for RISC-V and set the configuration: NOTE: We are using an older version of the toolchain. Configuration: 32-bit RISC-V core (RV32IM) with ZICSR extension

git clone --recursive https://github.com/riscv/riscv-gnu-toolchain
cd riscv-gnu-toolchain
./configure --prefix=/opt/riscv32 --with-arch=rv32im_zicsr --with-abi=ilp32 --with-isa-spec=2.2
make

Note that ilp32 specifies that int, long, and pointers are all 32-bits After the configuration is completed, run the make. Note that make also performs an install into the path specified by --prefix: /opt/riscv32.

Then, check the files that were installed:

cd /opt/riscv32
tree -L 2 -d

Later, add the environment variable to the .bashrc file:

export PATH=/opt/riscv32/bin:$PATH

Close the terminal, open a new one and check if the system is working:

riscv32-unknown-elf-gcc --version
riscv32-unknown-elf-objcopy --version

For further details, see the official repository: RISC-V toolchain

2. Install BENDER:

Follow the steps shown in the official repository: BENDER. Note: You need to install rust beforehand. Use the following command to install BENDER(once you have rust):

cargo install bender --version 0.28.1

Check that the installation was correct:

bender --version

3. Install VIVADO:

Vivado is downloaded from the website: Vivado

It is of paramount importance to install a couple of additional dependencies before running the installation program to avoid errors and get stuck when installing Vivado. To install them:

sudo apt-get update -y
sudo apt-get install -y libncurses5-dev libncursesw5-dev libncurses5 libtinfo5 libtinfo-dev

Then, follow these steps to successfully install Vivado:

1. Go to the website, select the proper version of Vivado(The system has been tested with the 2023.1 version)
2. Once it is downloaded, you get a .tar/.gz file that has to be extracted.
3. Make a directory on the /opt/ and make it writeable:

sudo mkdir /opt/Xilinx
sudo chmod -R 777 /opt/Xilinx

4. Go to the extracted folder and run sudo ./xsetup. This is going to open the installer.
5. Complete all the requirements asked by the installer and be sure to select the installation directory as /opt/Xilinx.
6. Once this process is finished, add the following command do the .bashrc file:

source /opt/Xilinx/Vivado/$Versionofvivado/settings64.sh

7. Close the terminal and open a new one. From now on, you can open Vivado from the terminal by writing "vivado". Note:this opens the GUI.

Moreover, you have to manually install the cable drivers for Vivado to recognize the FPGAs. To do so, you shold do the following:

cd /tools/Xilinx/Vivado/$Versionofvivado/data/xicom/cable_drivers/lin64/install_script/install_drivers
sudo ./intall_drivers

Finally, you have to add the PYNQ-Z1 board file to Vivado:

1. Go to the PYNQ: Board files and download the file corresponding to the PYNQ-Z1. This will download a .zip file

2. Go to:

cd /tools/Xilinx/Vivado/$Versionofvivado/data/boards/board_files

and extract the file here.

If Vivado is open, it must be restarted to load in the board files before a new project can be created.

For additional informatin regarding the installation of Vivado, please refer to Installing Vivado, Vitis, and Digilent Board Files