Value command¶

A useful mental model: value is a rough CLI equivalent of an initial block that waits until <at> and then $displays the selected signals — except it samples an existing dump instead of modifying the simulation.

Use value when you want one trustworthy snapshot instead of a time range.

It is the fastest way to answer questions like:

what was state at reset release,
what did valid, ready, and data look like on this cycle,
did two related signals agree at a specific timestamp.

In practice, value usually comes after info (to get time units and bounds) and scope or signal (to find the right names).

For exact syntax and flags, run wavepeek help value.

Start with one point-in-time snapshot¶

If you already know the canonical signal paths, sample them directly:

$ wavepeek value --waves path/to/dump.vcd --at 10ns --signals top.clk,top.data
@10ns
top.clk 1'h1
top.data 8'h0f

Use this when you already have full paths from signal, logs, or earlier queries.

Shorten deep names with `--scope`¶

When several signals live in the same scope, set that scope once and keep --signals relative:

$ wavepeek value --waves path/to/dump.vcd --at 10ns --scope top --signals clk,data
@10ns
clk 1'h1
data 8'h0f

This is usually the most convenient form for manual debugging.

Keep short input names but print canonical paths¶

Add --abs when you want scope-relative input but fully qualified output:

$ wavepeek value --waves path/to/dump.vcd --at 10ns --scope top --signals clk,data --abs
@10ns
top.clk 1'h1
top.data 8'h0f

Use this when you plan to paste results into notes, bugs, or follow-up commands.

Remember that sampling is state-at-time, not change-at-time¶

value returns the latest known value at or before --at. The timestamp does not need to be a transition point:

$ wavepeek value --waves path/to/dump.vcd --at 7ns --scope top --signals clk,data
@7ns
clk 1'h1
data 8'h00

Use this for spot checks between edges or between visible value changes.

Use JSON for scripts and agents¶

--json returns a stable machine-readable envelope:

$ wavepeek value --waves path/to/dump.vcd --at 10ns --scope top --signals clk,data --json
{"$schema":"https://raw.githubusercontent.com/kleverhq/wavepeek/v0.5.0/schema/wavepeek.json","command":"value","data":{"time":"10ns","signals":[{"path":"top.clk","value":"1'h1"},{"path":"top.data","value":"8'h0f"}]},"warnings":[]}

Use this when another tool needs deterministic parsing instead of human formatting.

Non-obvious behavior¶

--signals order is preserved exactly, including duplicates.
Without --scope, names in --signals are treated as canonical full paths.
With --scope, names in --signals must stay scope-relative. Do not mix relative names and full paths in one request.
--abs affects only human output. With --json, canonical paths are emitted either way.
--at accepts dump start and dump end; both bounds are inclusive.
Time tokens must be integer plus unit. 10ns is valid; 10 and 1.5ns are errors.
If a signal has no sampled value at or before the requested time, the command fails instead of inventing a default.
value does not truncate output and does not use --max; result size is bounded by the signals you requested.
Values are printed as Verilog literals. Non-bit-vector dump encodings are currently rejected by this command.