Stratus

Name

Stratus - Procedural design language based upon Python

Description

Stratus is a set of Python methods/functions dedicated to procedural generation purposes. From a user point of view, Stratus is a circuit's description language that allows Python programming flow control, variable use, and specialized functions in order to handle vlsi objects.

Based upon the Hurricane data structures, the Stratus language gives the user the ability to describe netlist and layout views.

Creation of a cell

A cell is a hierachical structural description of a circuit in terms of ports (I/Os), signals (nets) and instances.

The creation of a cell is done by creating a new class, derivating for class Model, with different methods :

• Method Interface : Description of the external ports of the cell :
  • SignalIn, SignalOut, ...
• Method Netlist : Description of the netlist of the cell :
  • Inst, Signal
• Method Layout : Description of the layout of the cell :
  • Place, PlaceTop, PlaceBottom, PlaceRight, PlaceLeft ...

Two methods are provided :

• Method View : Opens/Refreshes the editor in order to see the created layout
• Method Save : Saves the created cell
  • no argument : creation of a netlist file (format file thanks to CRL_OUT_LO)
  • PHYSICAL : creation of a netlist file AND a layout file (format files thanks to CRL_OUT_LO and CRL_OUT_PH)
  • STRATUS : creation of a python/stratus file
    • FileName : optionnal argument when using Save(STRATUS) in order to choose the name of the file to be generated
    • Be careful : if one wants to create a stratus file AND a netlist, always use Save(STRATUS) before Save() !

Syntax

A Stratus file must have a .py extension and must begin as follow :

#!/usr/bin/env python

from stratus import *

The creation of a class is done as follow :

class myClass ( Model ) :
    ...
    
exemple = myClass ( name, param )

In order to execute a Stratus file (named file for example), one has two choices :

python file.py

Or :

chmod u+x file.py
./file.py

The names used in Stratus, as arguments to Stratus functions, should be alphanumerical, including the underscore. The arguments of Stratus are case sensitive, so VDD is not equivalent to VDD.

Vectorized connectors or signal can be used using the [N:M] construct.

Syntax highlighting

When using vi, it's possible to have the right syntax highlighting when using vi :

• Commands to do when you want to change once the coloration of your file :

:syntax off
:source /asim/coriolis/share/etc/stratus.vim

• Modification of your .vimrc in order to have the syntax highlighting each time you open a file :

syntax off
autocmd BufRead,BufNewfile *.py so /asim/coriolis/share/etc/stratus.vim
syntax on

Environment variables

• CRL_IN_LO, default value : def
• CRL_OUT_LO, default value : def
• CRL_IN_PH, default value : def
• CRL_OUT_PH, default value : def
• CRL_CATA_LIB, default value : .
• CRL_CATAL_NAME, default value : CATAL

Example

You can see a concrete example at : Example

See Also

Netlist Layout Place and Route Virtual libraty Instanciation facilities