```
yosys -- Yosys Open SYnthesis Suite
-Copyright (C) 2012 - 2017 Clifford Wolf <clifford@clifford.at>
+Copyright (C) 2012 - 2018 Clifford Wolf <clifford@clifford.at>
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
or the 2-clause BSD license).
-Web Site
-========
+Web Site and Other Resources
+============================
More information and documentation can be found on the Yosys web site:
-http://www.clifford.at/yosys/
+- http://www.clifford.at/yosys/
+
+The "Documentation" page on the web site contains links to more resources,
+including a manual that even describes some of the Yosys internals:
+- http://www.clifford.at/yosys/documentation.html
+
+The file `CodingReadme` in this directory contains additional information
+for people interested in using the Yosys C++ APIs.
+
+Users interested in formal verification might want to use the formal verification
+front-end for Yosys, SymbiYosys:
+- https://symbiyosys.readthedocs.io/en/latest/
+- https://github.com/YosysHQ/SymbiYosys
+
Setup
======
On FreeBSD system use gmake instead of make. To run tests use:
% MAKE=gmake CC=cc gmake test
+For Cygwin use the following command to install all prerequisites, or select these additional packages:
+
+ setup-x86_64.exe -q --packages=bison,flex,gcc-core,gcc-g++,git,libffi-devel,libreadline-devel,make,pkg-config,python3,tcl-devel
+
There are also pre-compiled Yosys binary packages for Ubuntu and Win32 as well
as a source distribution for Visual Studio. Visit the Yosys download page for
more information: http://www.clifford.at/yosys/download.html
To build Yosys simply type 'make' in this directory.
$ make
- $ make test
$ sudo make install
Note that this also downloads, builds and installs ABC (using yosys-abc
as executable name).
+Tests are located in the tests subdirectory and can be executed using the test target. Note that you need gawk as well as a recent version of iverilog (i.e. build from git). Then, execute tests via:
+
+ $ make test
+
Getting Started
===============
yosys> read_verilog tests/simple/fiedler-cooley.v
-writing the design to the console in yosys's internal format:
+writing the design to the console in Yosys's internal format:
yosys> write_ilang
=================================
The following Verilog-2005 features are not supported by
-yosys and there are currently no plans to add support
+Yosys and there are currently no plans to add support
for them:
- Non-synthesizable language features as defined in
storage element. The register itself will always have all bits set
to 'x' (undefined). The variable may only be used as blocking assigned
temporary variable within an always block. This is mostly used internally
- by yosys to synthesize Verilog functions and access arrays.
+ by Yosys to synthesize Verilog functions and access arrays.
-- The ``onehot`` attribute on wires mark them as onehot state register. This
+- The ``onehot`` attribute on wires mark them as one-hot state register. This
is used for example for memory port sharing and set by the fsm_map pass.
- The ``blackbox`` attribute on modules is used to mark empty stub modules
passes to identify input and output ports of cells. The Verilog backend
also does not output blackbox modules on default.
+- The ``dynports'' attribute is used by the Verilog front-end to mark modules
+ that have ports with a width that depends on a parameter.
+
+- The ``hdlname'' attribute is used by some passes to document the original
+ (HDL) name of a module when renaming a module.
+
- The ``keep`` attribute on cells and wires is used to mark objects that should
never be removed by the optimizer. This is used for example for cells that
have hidden connections that are not part of the netlist, such as IO pads.
through the synthesis. When entities are combined, a new |-separated
string is created that contains all the string from the original entities.
-- In addition to the ``(* ... *)`` attribute syntax, yosys supports
+- In addition to the ``(* ... *)`` attribute syntax, Yosys supports
the non-standard ``{* ... *}`` attribute syntax to set default attributes
for everything that comes after the ``{* ... *}`` statement. (Reset
by adding an empty ``{* *}`` statement.)
- In module parameter and port declarations, and cell port and parameter
- lists, a trailing comma is ignored. This simplifies writing verilog code
+ lists, a trailing comma is ignored. This simplifies writing Verilog code
generators a bit in some cases.
- Modules can be declared with ``module mod_name(...);`` (with three dots
- The system functions ``$allconst`` and ``$allseq`` can be used to construct
formal exist-forall problems. Assumptions only hold if the trace satisfies
- the assumtion for all ``$allconst/$allseq`` values. For assertions and cover
+ the assumption for all ``$allconst/$allseq`` values. For assertions and cover
statements it is sufficient if just one ``$allconst/$allseq`` value triggers
the property (similar to ``$anyconst/$anyseq``).
-- Wires/registers decalred using the ``anyconst/anyseq/allconst/allseq`` attribute
+- Wires/registers declared using the ``anyconst/anyseq/allconst/allseq`` attribute
(for example ``(* anyconst *) reg [7:0] foobar;``) will behave as if driven
by a ``$anyconst/$anyseq/$allconst/$allseq`` function.
into a design with ``read_verilog``, all its packages are available to
SystemVerilog files being read into the same design afterwards.
+- SystemVerilog interfaces (SVIs) are supported. Modports for specifying whether
+ ports are inputs or outputs are supported.
+
Building the documentation
==========================
Notes:
-- To run `make manual` you need to have installed yosys with `make install`,
+- To run `make manual` you need to have installed Yosys with `make install`,
otherwise it will fail on finding `kernel/yosys.h` while building
`PRESENTATION_Prog`.
projects / yosys.git / blobdiff