NAME

       ghdl - VHDL compiler/simulator

SYNOPSIS

       ghdl [command] [options] files...
       ghdl-gcc [command] [options] files...
       ghdl-llvm [command] [options] files...
       ghdl-mcode [command] [options] files...

DESCRIPTION

       This  manual  page  documents  briefly the ghdl command.  This manual page was written for
       user of man, but is not as complete as the reference documentation.

       Instead, users should read the GHDL texinfo manual

       The Debian package supports installing multiple GHDL backends at the same time.  The  GHDL
       executable  ghdl  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 ghdl-mcode, ghdl-gcc and ghdl-llvm respectively.
       Alternatively, you can run ghdl with the GHDL_BACKEND environment variable set  to  mcode,
       gcc  or  llvm  to  select  a  backend.  If the backend in GHDL_BACKEND is not installed or
       invalid, the wrapper will silently revert to selecting  the  first  installed  backend  it
       finds.

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.

       Basic commands:

       -a     Analysis, i.e. ghdl -a file.vhdl

       -e     Elabortation, i.e. ghdl -e unit_name

       -r     Run: run the simulation, i.e. ghdl -r unit_name

       -s     Syntax-check, i.e. ghdl -s file.vhdl

       --clean
              Clean: remove generated files, i.e. ghdl --clean

       -h, --help
              Help, i.e. ghdl --help

       --version
              Version, i.e. ghdl --version

       Basic options:

       --work=NAME
              Name of the WORK library, i.e.  ghdl -a --work=foo foo.vhdl

       --std=STD
              Which VHDL standard (87|93|93c|00|02), i.e. ghdl -a --std=87 old.vhdl

       --ieee=VER
              Which  IEEE  library  (none|standard|synopsys|mentor), i.e. ghdl -a --ieee=synopsys
              broken.vhdl

       --no-vital-checks
              Disable   VITAL   restriction   checking,   i.e.    ghdl    -a    --no-vital-checks
              unsupported_vital.vhdl

       There are many more modes and options; please consult the documentation.

       Executables  created by GHDL have addition simulation options. The most important ones are
       listed below:

       --help Show options for simulation and execution.

       --assert-level=LEVEL
              Assert level at which to stop  simulation  (none|note|warning|error|failure),  i.e.
              ./touchy_design --assert-level=note

       --stop-time=TIME
              Stop simuation after TIME, i.e. ./design --stop-time=50ns

       --vcd=FILENAME
              Dump  VCD to FILENAME (a waveform dump, viewable with--for instance--gtkwave), i.e.
              ./design --vcd=design.vcd

       --sdf=[TYPE=]PATH=FILENAME
              Back annotate SDF onto design using TYPE (min|typ|max), instance PATH, and SDF file
              FILENAME, i.e. ./sdf_design --sdf=typ=top/inst=inst.sdf

SEE ALSO

       gtkwave(1)

       The    texinfo    manual   fully   documents   GHDL.   You   may   also   browse   it   at
       <https://ghdl.github.io/ghdl/>.

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.

                                           Jan 14, 2018                                   GHDL(1)