virtualdevboard is a framework for creating virtual development boards. A virtual development board is an FPGA/ASIC development board that is entirely emulated on a PC. The FPGA/ASIC logic is converted into cycle accurate C++ models using Verilator. The peripherals (other components) on the board are emulated using graphical components (e.g. LEDs, 7-segment Display, VGA), abstracted (e.g. SDRAM memories), or by accessing the host PCs hardware and OS resources directly (e.g. UART, ethernet, ...)
- Verilator
- gmake
- C++20 capable compiler
- wxWidgets 3.2.6 or newer
- Doxygen
- Graphviz
The software consists out of two different components, one is the FPGA/ASIC logic, which is translated into C++ code with verilator. The second part is the GUI with the virtual components. The verilated design and the GUI run in a different thread and have different methods to communicate between the threads, it is possible to run the design without the use of the GUI.
Full software documentation can be found here.
All FPGA/ASIC logic is converted into C++ code with verilator, this is then controlled from the virtual development board. The design is controlled through the main testbench and holds the complete timing interface of the design. It cycles step by step through the design by changing the clocks when needed. This means that it evaluates the next clock edge, toggles the clock and evaluates the full design. Which is then repeated untill a finish is received or the simulation is stopped.
The verilated design communicates with the GUI through a specific interface. This interface is introduced so that it's possible to change the underlaying GUI framework. In the main design of the GUI the general control is instantiated, with this comes the start, pause and stop button.
Peripherals are created as virtual components. Those components can be connected with the verilated design and/or shown on the GUI, this is specific to the peripheral and the usage of it. Within the initialization file it is determined where a component is placed in the GUI, which is always relative to the top left corner.