diff options
Diffstat (limited to 'README.md')
| -rw-r--r-- | README.md | 38 |
1 files changed, 29 insertions, 9 deletions
@@ -69,7 +69,7 @@ prerequisites for building yosys: graphviz xdot pkg-config python3 libboost-system-dev \ libboost-python-dev libboost-filesystem-dev zlib1g-dev -Similarily, on Mac OS X Homebrew can be used to install dependencies: +Similarily, on Mac OS X Homebrew can be used to install dependencies (from within cloned yosys repository): $ brew tap Homebrew/bundle && brew bundle @@ -364,20 +364,19 @@ Verilog Attributes and non-standard features it as the external-facing pin of an I/O pad, and prevents ``iopadmap`` from inserting another pad cell on it. -- The module attribute ``abc9_box_id`` specifies a positive integer linking a - blackbox or whitebox definition to a corresponding entry in a `abc9` - box-file. +- The module attribute ``abc9_lut`` is an integer attribute indicating to + `abc9` that this module describes a LUT with an area cost of this value, and + propagation delays described using `specify` statements. + +- The module attribute ``abc9_box`` is a boolean specifying a black/white-box + definition, with propagation delays described using `specify` statements, for + use by `abc9`. - The port attribute ``abc9_carry`` marks the carry-in (if an input port) and carry-out (if output port) ports of a box. This information is necessary for `abc9` to preserve the integrity of carry-chains. Specifying this attribute onto a bus port will affect only its most significant bit. -- The port attribute ``abc9_arrival`` specifies an integer (for output ports - only) to be used as the arrival time of this sequential port. It can be used, - for example, to specify the clk-to-Q delay of a flip-flop for consideration - during `abc9` techmapping. - - The module attribute ``abc9_flop`` is a boolean marking the module as a flip-flop. This allows `abc9` to analyse its contents in order to perform sequential synthesis. @@ -387,6 +386,10 @@ Verilog Attributes and non-standard features according to the type of the always. These are checked for correctness in ``proc_dlatch``. +- The cell attribute ``wildcard_port_conns`` represents wildcard port + connections (SystemVerilog ``.*``). These are resolved to concrete + connections to matching wires in ``hierarchy``. + - 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 @@ -437,6 +440,17 @@ Verilog Attributes and non-standard features ... endmodule +- The ``wiretype`` attribute is added by the verilog parser for wires of a + typedef'd type to indicate the type identifier. + +- Various ``enum_{width}_{value}`` attributes are added to wires of an + enumerated type to give a map of possible enum items to their values. + +- The ``enum_base_type`` attribute is added to enum items to indicate which + enum they belong to (enums -- anonymous and otherwise -- are + automatically named with an auto-incrementing counter). Note that enums + are currently not strongly typed. + - A limited subset of DPI-C functions is supported. The plugin mechanism (see ``help plugin``) can be used to load .so files with implementations of DPI-C routines. As a non-standard extension it is possible to specify @@ -527,6 +541,12 @@ from SystemVerilog: SystemVerilog files being read into the same design afterwards. - typedefs are supported (including inside packages) + - type identifiers must currently be enclosed in (parentheses) when declaring + signals of that type (this is syntactically incorrect SystemVerilog) + - type casts are currently not supported + +- enums are supported (including inside packages) + - but are currently not strongly typed - SystemVerilog interfaces (SVIs) are supported. Modports for specifying whether ports are inputs or outputs are supported. |