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Diffstat (limited to 'README.md')
| -rw-r--r-- | README.md | 18 |
1 files changed, 15 insertions, 3 deletions
@@ -311,12 +311,24 @@ Verilog Attributes and non-standard features that have the same ports as the real thing but do not contain information on the internal configuration. This modules are only used by the synthesis passes to identify input and output ports of cells. The Verilog backend - also does not output blackbox modules on default. + also does not output blackbox modules on default. ``read_verilog``, unless + called with ``-noblackbox`` will automatically set the blackbox attribute + on any empty module it reads. -- The ``dynports'' attribute is used by the Verilog front-end to mark modules +- The ``noblackbox`` attribute set on an empty module prevents ``read_verilog`` + from automatically setting the blackbox attribute on the module. + +- The ``whitebox`` attribute on modules triggers the same behavior as + ``blackbox``, but is for whitebox modules, i.e. library modules that + contain a behavioral model of the cell type. + +- The ``lib_whitebox`` attribute overwrites ``whitebox`` when ``read_verilog`` + is run in `-lib` mode. Otherwise it's automatically removed. + +- 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 +- 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 |