Generate and View Waveforms with NucleusRV

NucleusRV supports waveform tracing during simulation to help with debugging.

Enabling Waveform Tracing

Pass the --trace flag to Verilator during compilation:

verilator --cc --exe --build --trace --no-timing $NRV_ROOT/tb_Top.cpp Top.v

Where Waveforms are Saved

During simulation, a VCD file is generated at logs/top.vcd within your simulation directory.

Opening Waveforms in GTKWave

Use GTKWave to view the signal transitions:

gtkwave logs/top.vcd

Key Signals to Watch

• clock and reset

• io_imemReq_valid / io_imemRsp_valid (Instruction Fetch)

• io_dmemReq_valid / io_dmemRsp_valid (Data Memory Access)

• io_pin (Write-back data output)