Connect to a SimVision instance running mcp_bridge.tcl.

Args: host: SimVision host (use localhost with SSH tunnel for remote). port: TCP port of the Tcl bridge (default 9876). timeout: Connection timeout in seconds.

Disconnect from the SimVision bridge.

Run the simulation, optionally for a specified duration.

Args: duration: Simulation time to run (e.g. "100ns", "1us"). Empty = run until breakpoint or end. timeout: MCP response timeout in seconds (default 600s for gate-level sim support).

Stop a running simulation.

Restart the simulation from time 0.

Get current simulation status (time, scope, state).

Set a conditional breakpoint in the simulation.

Args: condition: Tcl expression (e.g. "{/tb/dut/state == 3}"). name: Optional breakpoint name.

Read current values of one or more signals.

Args: signals: List of signal paths (e.g. ["/tb/dut/clk", "/tb/dut/data[7:0]"]).

Get detailed information about a signal (type, width, direction).

Args: signal: Full hierarchical signal path.

Find all drivers of a signal (useful for X/Z debugging).

Args: signal: Full hierarchical signal path.

List signals in a scope, optionally filtered by pattern.

Args: scope: Hierarchical scope path (e.g. "/tb/dut"). pattern: Glob pattern to filter signals (default "*").

Force-deposit a value onto a signal.

Args: signal: Full hierarchical signal path. value: Value to deposit (e.g. "1'b1", "8'hFF", "0").

Release a previously deposited signal, restoring driven value.

Args: signal: Full hierarchical signal path.

Add signals to the SimVision waveform viewer.

Args: signals: List of signal paths to add. group_name: Optional group name for organizing signals.

Set the waveform viewer time range (zoom to region).

Args: start_time: Start time (e.g. "0ns"). end_time: End time (e.g. "100ns").

Set a waveform cursor to a specific time.

Args: time: Simulation time (e.g. "50ns"). cursor_name: Cursor name (default "TimeA").

Capture a screenshot of the SimVision waveform window.

Returns the screenshot as a PNG image that Claude can analyze.

Comprehensive debug snapshot: simulation state + signal values + screenshot + debugging guide.

Returns a combined text report and waveform screenshot for AI-assisted hardware debugging.

Safely shutdown the simulator, preserving SHM waveform data.

Closes all SHM databases and terminates xmsim gracefully. Always use this instead of disconnect_simulator when ending a debug session. WARNING: exit or pkill will lose SHM data. This is the only safe way.

Set a watchpoint to stop simulation when a signal matches a condition.

The simulation will automatically stop at the exact clock edge where the condition becomes true. Much more efficient than manual probing.

Args: signal: Full hierarchical signal path (e.g. "top.dut.r_state[3:0]"). op: Comparison operator ("==", "!=", ">", "<", ">=", "<="). value: Target value in Verilog format (e.g. "8'h10", "4'b1010").

Clear watchpoints. Use "all" to clear all, or a specific stop ID.

Args: watch_id: Watchpoint ID to clear, or "all" for all watchpoints.

Control SHM waveform recording to manage dump file size.

Disable probes during uninteresting simulation periods to save disk space. Re-enable before the region of interest. Optionally target a specific scope.

Args: mode: "enable" to start recording, "disable" to pause, "status" to check. scope: Hierarchical scope to target (e.g. "top.hw.u_ext"). Empty = all probes.

Save a simulation checkpoint for later restoration.

Checkpoints capture the complete simulator state. Use restore_checkpoint to return to this point without re-simulating from time 0.

Args: name: Checkpoint name (alphanumeric, e.g. "chk_10ms"). Auto-generated if empty.

Restore simulation to a previously saved checkpoint.

Args: name: Checkpoint name to restore. Empty = last saved checkpoint.

Find when a signal condition first becomes true using automated binary search.

Internally saves checkpoints and repeatedly restores/runs with watchpoints to narrow down the exact time. Returns iteration log and final time range.

Args: signal: Full hierarchical signal path. op: Comparison operator (e.g. "=="). value: Target value (e.g. "8'h11"). start_ns: Start of search range in nanoseconds. end_ns: End of search range in nanoseconds. precision_ns: Stop when range is narrower than this (default 1000ns).