Waveform files · Soft Forge HDL Studio

Open a .ghw or .vcd file from the Explorer, or with HDL Studio: Open Waveform File (GHW, VCD)…, and it shows in the signal viewer. The file is watched: simulate again and the view follows, keeping its zoom and the expanded scopes.

dds_tb.ghw opened from the Explorer: a direct digital synthesiser with its state machine by name, hex buses, and the sine output as an analog trace. — `dds_tb.ghw` from `examples/cmake`: the `stage` enumeration by name, `sample` and `analog` as analog traces, `End` and `Home`.

GHW or VCD#

	GHW (`--wave=file.ghw`)	VCD (`--vcd=file.vcd`)
Bits and vectors	yes, with the VHDL type (`signed` vectors plot as signed)	yes
Integers, reals	yes	integers as 32-bit vectors, reals
Enumerations, booleans, physical values	yes, by name	no
Records, arrays of vectors	yes, as expandable groups	no
Strings	yes	no
Written by	GHDL	any simulator

Prefer GHW for a GHDL design: it is what makes a state machine readable. A GHW file can be gzipped.

Recording#

While debugging: add either option to simArgs of a launch configuration, or keep simulation.record on in the workspace file.
Headless: hdl run always records <workDir>/<testbench>.ghw, and adds a VCD with --vcd out.vcd.
xsim: the xsim stage of the Vivado flow records <workDir>/<testbench>.xsim.vcd and opens it in the viewer.

Reading values from the terminal#

hdl signals and hdl waves read the same files without a window:

hdl signals --file .hdl-studio/counter_tb.ghw --at 50ns --filter count
hdl waves .hdl-studio/counter_tb.ghw --signal count --from 10ns --to 100ns