yosys/docs/source/using_yosys/synthesis/proc.rst

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Converting process blocks
~~~~~~~~~~~~~~~~~~~~~~~~~
.. role:: yoscrypt(code)
:language: yoscrypt
The Verilog frontend converts ``always``-blocks to RTL netlists for the
expressions and "processess" for the control- and memory elements. The `proc`
command then transforms these "processess" to netlists of RTL multiplexer and
register cells. It also is a macro command that calls the other ``proc_*``
commands in a sensible order:
.. literalinclude:: /code_examples/macro_commands/proc.ys
:language: yoscrypt
:start-after: #end:
:caption: Passes called by `proc`
After all the ``proc_*`` commands, `opt_expr` is called. This can be disabled by
calling :yoscrypt:`proc -noopt`. For more information about `proc`, such as
disabling certain sub commands, see :doc:`/cmd/proc`.
Many commands can not operate on modules with "processess" in them. Usually a
call to `proc` is the first command in the actual synthesis procedure after
design elaboration.
Example
^^^^^^^
.. todo:: describe ``proc`` images
|code_examples/synth_flow|_.
.. |code_examples/synth_flow| replace:: :file:`docs/source/code_examples/synth_flow`
.. _code_examples/synth_flow: https://github.com/YosysHQ/yosys/tree/main/docs/source/code_examples/synth_flow
.. literalinclude:: /code_examples/synth_flow/proc_01.v
:language: verilog
:caption: :file:`proc_01.v`
.. literalinclude:: /code_examples/synth_flow/proc_01.ys
:language: yoscrypt
:caption: :file:`proc_01.ys`
.. figure:: /_images/code_examples/synth_flow/proc_01.*
:class: width-helper invert-helper
.. figure:: /_images/code_examples/synth_flow/proc_02.*
:class: width-helper invert-helper
.. literalinclude:: /code_examples/synth_flow/proc_02.v
:language: verilog
:caption: :file:`proc_02.v`
.. literalinclude:: /code_examples/synth_flow/proc_02.ys
:language: yoscrypt
:caption: :file:`proc_02.ys`
.. figure:: /_images/code_examples/synth_flow/proc_03.*
:class: width-helper invert-helper
.. literalinclude:: /code_examples/synth_flow/proc_03.ys
:language: yoscrypt
:caption: :file:`proc_03.ys`
.. literalinclude:: /code_examples/synth_flow/proc_03.v
:language: verilog
:caption: :file:`proc_03.v`