Load a design into the OpenSTA session. Call this once before any analysis.

liberty: Liberty (.lib) file path, or a list of paths verilog: gate-level netlist (.v) path top: top module name to link sdc: SDC constraints file (optional but required for meaningful timing) spef: parasitics file (optional; without it delays use wire-load / no parasitics)

Returns per-step timings and a digest of warnings. Warnings raised here (unmatched SPEF nets, missing cells, unconstrained ports) affect every later result, so read them. Starts a new analysis state (see get_conditions). Loads on top of the running sta: to drop earlier constraints and run_tcl changes, call restart_session first.

Timing and size summary as numbers: worst setup/hold slack, TNS, WNS, minimum clock period and fmax per clock, design-rule violation counts, cell and net counts.

Report timing paths (OpenSTA report_checks).

path_delay: "max" = setup paths, "min" = hold paths path_count: paths per path group (-group_path_count) scope: "reg2reg" = register to register only, "in2reg" = from input ports, "reg2out" = to output ports, "all" = no restriction from_pin / to_pin: restrict to a start or end point (pin, port or instance name; bus bits like reg_next_pc[31] are fine, they are quoted for you) fields: include input-pin rows (separates wire from cell delay) and slew, capacitance, fanout and net columns format: "end" and "summary" are one line per path; "json" only if this OpenSTA supports it (check with run_tcl "help report_checks") timeout_s: 0 = wait as long as it takes (a stalled sta is still detected)

Report power by group (sequential, combinational, clock, macro, pad) and component (internal, switching, leakage), in watts.

top_instances: also list this many highest-power instances (0 = none) format: "text" table or "json" (the instance list is always text)

The result states where switching activity came from: a VCD/SAIF read through run_tcl, or OpenSTA's default activity (then values are estimates).

Run any OpenSTA Tcl command(s) in the live session.

Rules:

• OpenSTA syntax. Unsure of a command name? Use find_commands. Unsure of its options? Run help <command> here first.

• Wrap bus bit names in braces: -to {reg_next_pc[31]}.

• exec, exit, socket, source, cd and load are disabled. Files (reports via > file, write_* commands) can be written only under the session directory shown by get_status.

• State changes made here (read_*, set_*, create_*, ...) stay in effect, start a new analysis state and are listed by get_conditions.

• The script's Tcl return value is returned too, so puts is not needed.

• Long output is truncated; narrow the query instead of asking for everything. timeout_s: 0 = no limit. sta is never restarted automatically.

Names of the OpenSTA commands matching a glob pattern (e.g. "power", "report_*"). Use this when you do not know a command's name or run_tcl answered "invalid command name". Returns names only; read a command's description and options with run_tcl "help ".

What the OpenSTA session is doing. Safe to call at any time, including while another tool is waiting: shows the running command and its elapsed time, whether sta is computing or idle, the loaded design and its state number, constraint changes made through run_tcl, and the session log directory.

The analysis conditions behind a result: the Liberty, netlist, SDC and SPEF files (full paths), every constraint change made through run_tcl since, the switching-activity source and the scenes. Analysis results end with "[conditions #n]"; pass that n as state to see the conditions they were computed under, or 0 for the current state. Answers from the session journal, so earlier states can be read even after sta died.

Stop the sta process and start a fresh one. The loaded design and any constraint changes are lost; call load_design again. Use this after get_status reports sta as exited, stalled, or holding an unfinished command.