This project implements a fully functional scientific calculator in hardware using an FPGA. It includes a custom soft CPU, microcode firmware, and supporting tools.
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Try it in a web browser:
Project Structure
| Folder |
Description |
verilog/ |
SystemVerilog source files for the CPU, ALU, I/O, and test benches |
ucode/ |
Microcode (firmware) for the soft CPU |
quartus/ |
Quartus project files for FPGA synthesis |
modelsim/ |
ModelSim simulation setup |
Qt/ |
Qt-based simulator and debugger (uses Verilator) |
calctest/ |
Command-line test harness for hardware verification (uses Verilator) |
tools/ |
Assembler and script compiler for the microcode |
Pathfinding/ |
Algorithm research and verification projects |
Quick Start
The fastest way to try the calculator is to build the Qt simulator:
From WSL2
cd /mnt/c/Projects/FPGA-Calculator/verilog
make qt
Then open Qt/Calculator.pro in Qt Creator and build for "Desktop Qt MSVC2022 64 Bit".
See the verilog/ and Qt/ folders for detailed instructions.
Required Tools
Install these tools depending on your target:
| Tool |
Purpose |
Notes |
| Verilator |
Verilog simulation |
Required for Qt simulator |
| Qt |
Desktop/WebAssembly/Android app |
Version 6.9+ |
| Quartus |
FPGA synthesis |
Version 13.0 SP1 for Cyclone II |
| ModelSim |
Waveform simulation |
Optional |
| Visual Studio 2022 |
C++ compiler for Qt |
Community Edition |
| Python 3 |
Assembler and tools |
|
Verilator Setup
Verilator runs in WSL2 (Windows Subsystem for Linux). The project source files reside on a Windows partition and are accessed from WSL2.
| Target |
Verilator Version |
Notes |
| Desktop (Qt/MSVC) |
5.x (latest) |
Recommended |
| WebAssembly |
4.228 |
Required (no thread support) |
Install prerequisites
sudo apt-get install build-essential autoconf flex libfl-dev bison
Clone and build Verilator
git clone https://github.com/verilator/verilator
cd verilator
git checkout v5.042 # For Desktop, or v4.228 for WebAssembly
autoconf
./configure
make -j8
make test
Set environment (add to .bashrc for persistence)
export VERILATOR_ROOT=$(pwd)
Optionally install GtkWave for viewing waveforms:
sudo apt install gtkwave
Build Targets
| Target |
Command |
Description |
| Qt Simulator |
make qt in verilog/ |
Build for Qt desktop application |
| Calctest |
make calctest in verilog/, then make in calctest/ |
Command-line test harness |
| ModelSim |
make test_self in verilog/ |
CPU self-test for ModelSim |
| FPGA Hardware |
make revB in verilog/ |
Assemble microcode for RevB board |
See the README files in each subfolder for detailed build instructions:
Pathfinding Projects
Independent research and verification projects:
| Folder |
Description |
Pathfinding/Proto/ |
BCD arithmetic golden reference for hardware verification (submodule) |
Pathfinding/Proof/ |
Proofs of concept for complex operations using basic arithmetic |
Pathfinding/Methods/ |
C++ implementations of calculator algorithms (deprecated) |
Pathfinding/Input/ |
Numerical input state machine simulation |
Pathfinding/Mockup/ |
Keyboard layout design and user interaction testing |
License
This project is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
You are free to:
- Share - copy and redistribute the material in any medium or format
- Adapt - remix, transform, and build upon the material
Under the following terms:
- Attribution - You must give appropriate credit and indicate if changes were made
- NonCommercial - You may not use the material for commercial purposes
- ShareAlike - Contributions must be distributed under the same license
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