Xrun Debugger

Overview

A lightweight Verilog/SystemVerilog Debugger. It allows Cadence Xcelium Logic Simulator licensed users to interactively debug their designs & testbenches during simulation execution. Here's a list of features:

• Launch
• Breakpoints/Conditional Breakpoints
• Step In/Out/Over/Continue
• Variables
• Callstacks
• Debug console
• REPL Evaluation

Requirements

• Xcelium 22.09-s001
• VS Code (version 1.66.0 or later)

Install

Open VS Code and press F1 or Ctrl + Shift + P to open command palette, select Install Extension and type xrun-debug.

Or launch VS Code Quick Open (Ctrl + P), paste the following command, and press enter.

ext install boreas-technologies.xrun-debug

Use

• Launch VS Code
• Open a Verilog/SystemVerilog file to activate the extension
• Press F5

Options

Launch

• program - Absolute path to executable, or relative path if 'cwd' is specified. If the xrun tool has been exported to your user/global .bashrc, simply specify "xrun". If extensive configuration of the simulation or post-simulation handling of waveform databases is required, this can be a shell script calling xrun inlined, as long as it doesn't relinquish console output to another program (such as calling xrun with the -gui switch).
• cwd - The directory from which the executable program is called.
• args - The command line arguments passed to the xrun command.
  • "${command:SpecifyArgs}" - Prompt user for program arguments.
  • file.yml - Parse YAML configuration file under the "test" array and display a QuickPick to select an element as an argument.
  • A space-separated string or an array of string.
• problemMatchers - Lines that match against these keywords in the output console will be sent to stderr.
• stopOnEntry - Automatically stop after launch. Setting to false will cause simulator to run until the first user breakpoint.
• noDebug - Run simulation without debug.

Known Issues, Limitations and Workarounds

User-facing

• XrunDebug requires GNU Bash shell installed.
• Current execution require a bash script be wrapped around xrun in order to translate non-generic switch arguments:
  • Replace -i with -linedebug
• Non-UVM testbenches may not start properly because of the current startup sequence coupling with the stop_at_build switch and are therefore not recommended.
• stopAtEntry=false configurations may occasionally fail to relinquish output to the client console on the first debug session.

Internal

• Output-returning commands sent with the debugger stopped on a breakpoint (including the stop create command itself) may fail due to the Node.js child_process.stdout internal buffer keeping the expected output from being obtained in time and require manual flushing. Current workaround involves sending a puts command to Xcelium afterward in order to "shove" stdout.

License

This extension is licensed under MIT License.