HDL Simulation Skill

Overview

Expert skill for HDL simulation across multiple simulators, enabling comprehensive functional verification of FPGA designs.

Capabilities

• Generate simulation scripts (do files, tcl)
• Configure ModelSim/Questa simulations
• Configure Vivado Simulator (xsim)
• Configure VCS and Xcelium simulations
• Analyze waveforms for debugging
• Generate VCD and FSDB dumps
• Configure code coverage collection
• Support mixed-language simulation

Target Processes

• functional-simulation.js
• testbench-development.js
• uvm-testbench.js
• constrained-random-verification.js

Usage Guidelines

Simulator Setup

• Create project-specific compilation scripts
• Configure library mappings
• Set up include paths and search paths
• Define simulation options
• Configure waveform dump formats

ModelSim/Questa

vlib work
vlog -sv +incdir+../rtl ../rtl/*.sv
vsim -voptargs="+acc" tb_top
add wave -recursive /*
run -all

Vivado Simulator (xsim)

xvlog --sv ../rtl/*.sv
xelab -debug typical tb_top -s tb_sim
xsim tb_sim -runall

VCS

vcs -sverilog -debug_access+all -f filelist.f -o simv
./simv +vcs+vcdpluson

Waveform Analysis

• Identify timing relationships
• Trace signal propagation
• Compare expected vs. actual
• Use markers for measurements
• Create protocol decoders

Coverage Collection

• Statement coverage
• Branch coverage
• Toggle coverage
• FSM coverage
• Functional coverage (SystemVerilog)

Mixed-Language

• Compile VHDL and Verilog separately
• Use proper interface binding
• Handle type conversions
• Configure library order
• Test boundary conditions

Dependencies

• Simulator CLI integration
• Waveform viewer knowledge
• Coverage analysis tools