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.TH "GHDL" "1" "Jan 14, 2018" "" ""
.SH "NAME"
ghdl \- VHDL compiler/simulator
.SH "SYNOPSIS"
.B ghdl
.RI [ command ] " " [ options ] " files" ...
.br 
.B ghdl-gcc
.RI [ command ] " " [ options ] " files" ...
.br 
.B ghdl-llvm
.RI [ command ] " " [ options ] " files" ...
.br 
.B ghdl-mcode
.RI [ command ] " " [ options ] " files" ...
.br 
.SH "DESCRIPTION"
This manual page documents briefly the
.B ghdl
command.
This manual page was written for user of man, but is not as complete as the
reference documentation.
.PP 
Instead, users should read the GHDL texinfo manual
.PP
The Debian package supports installing multiple GHDL backends at the same time.
The GHDL executable \fBghdl\fR is actually a wrapper that will execute the first
installed backend it finds in the order mcode, gcc, llvm.
If you want to run GHDL with a specific backend you can directly run their
executable, named \fBghdl-mcode\fR, \fBghdl-gcc\fR and \fBghdl-llvm\fR
respectively.
Alternatively, you can run \fBghdl\fR with the \fIGHDL_BACKEND\fR environment
variable set to \fBmcode\fR, \fBgcc\fR or \fBllvm\fR to select a backend.
If the backend in \fIGHDL_BACKEND\fR is not installed or invalid, the wrapper
will silently revert to selecting the first installed backend it finds.
.SH "OPTIONS"
This program follows the usual GNU command line syntax, with long
options starting with two dashes (`\-').
A summary of the main modes and options is included below.
For a complete description, refer to the GHDL texinfo manual.
.PP 
Basic commands:
.TP 
.B \-a
Analysis, i.e. \fIghdl \-a file.vhdl\fP
.TP 
.B \-e
Elabortation, i.e. \fIghdl \-e unit_name\fP
.TP 
.B \-r
Run: run the simulation, i.e. \fIghdl \-r unit_name\fP
.TP 
.B \-s
Syntax\-check, i.e. \fIghdl \-s file.vhdl\fP
.TP 
.B \-\-clean
Clean: remove generated files, i.e. \fIghdl \-\-clean\fP
.TP 
.B \-h, \-\-help
Help, i.e. \fIghdl \-\-help\fP
.TP 
.B \-\-version
Version, i.e. \fIghdl \-\-version\fP
.PP 
Basic options:
.TP 
.B \-\-work=NAME
Name of the WORK library, i.e. \fI ghdl \-a \-\-work=foo foo.vhdl\fP
.TP 
.B \-\-std=STD
Which VHDL standard (87|93|93c|00|02), i.e. \fIghdl \-a \-\-std=87 old.vhdl\fP
.TP 
.B \-\-ieee=VER
Which IEEE library (none|standard|synopsys|mentor), i.e. \fIghdl \-a \-\-ieee=synopsys broken.vhdl\fP
.TP 
.B \-\-no\-vital\-checks
Disable VITAL restriction checking, i.e. \fIghdl \-a \-\-no\-vital\-checks unsupported_vital.vhdl\fP
.PP 
There are many more modes and options;
please consult the documentation.
.PP 
Executables created by GHDL have addition simulation options. The
most important ones are listed below:
.TP 
.B \-\-help
Show options for simulation and execution.
.TP 
.B \-\-assert\-level=LEVEL
Assert level at which to stop simulation (none|note|warning|error|failure), i.e. \fI./touchy_design \-\-assert\-level=note\fB
.TP 
.B \-\-stop\-time=TIME
Stop simuation after TIME, i.e. \fI./design \-\-stop\-time=50ns
.TP 
.B \-\-vcd=FILENAME
Dump VCD to FILENAME (a waveform dump, viewable with\-\-for instance\-\-\fBgtkwave\fP), i.e. \fI./design \-\-vcd=design.vcd
.TP
.B \-\-sdf=[TYPE=]PATH=FILENAME
Back annotate SDF onto design using TYPE (min|typ|max), instance PATH, and SDF file FILENAME, i.e. \fI./sdf_design \-\-sdf=typ=top/inst=inst.sdf\fP

.SH "SEE ALSO"
.TP
.BR gtkwave (1)
.PP
.br 
The texinfo manual fully documents GHDL. You may also browse it at
\fB<http://ghdl.free.fr/ghdl/index.html>\fP.
.SH "AUTHOR"
This manual page was written by Wesley J. Landaker
<wjl@icecavern.net>, for the Debian project (but may be used by
others). It is released under the same terms as GHDL, i.e. the GNU
General Public License. It was modified by Tristan Gingold to include
it in the GHDL sources.