DGC project

A system for the creation of digital circuits.

Overview

Digital circuits can be used to build some kind of hardware. Often a hardware is an application specific integrated circuit or a programmable logic array. In this both cases hardware is created from a 'netlist'. Such a netlist contains information about the connection of some basic building blocks (gates).

DGC is a system for the creation of netlist files by using an abstract spezification of digital systems. The following types of specification are supported:

PLA

Sum of product expression

BEX

Boolean expression

NEX

Numeric expression

KISS

State machine description

BMS

Burst mode specification, Subset of state machine description

DGD

Script language to build hierarchical designs

For the conversion from an abstract description to a netlist, DGC needs to know what kind of basic building blocks are available. Such a file is called a gate library.

Input Files

This is a list of currently supported input formats:

PLA (.pla, .pl)

This is a sum of product representation of several boolean functions. This format is used in the well known espresso tool (University of California). http://www-cad.eecs.berkeley.edu/Software/software.html

BEX (.bex, boolean expression)

This is a more readable format for boolean functions. See example.bex for a description.

NEX (.nex, numeric expression)

Extracts boolean functions from mathematical expressions. See example.nex for a description.

KISS (.kiss)

A description of a finite state machine. This file format is used by the tools KISS, NOVA and others. Some of these tooles can be found in the SIS package http://www-cad.eecs.berkeley.edu/Software/software.html The file example.kiss can be found in <installation-path>/share/dgc

BMS (.bms, burst mode spezification)

Also a file format for the description of finite state machines. It is a spezial restricted format to describe asynchronous state machines. A description of the format is included in the MINIMALIST package (Columbia University) http://www.cs.columbia.edu/async/

DGD (.dgd, digital gate design)

This is a small script language to import and use all supported file formats. See the file <installation-path>/share/dgc/d_latch.dgd for an example.

Output Files

EDIF (.edif)

The elecronic design interchange format (http://www.edif.org/). This is the most used and known format to store a netlist.

VHDL-netlist (.vhdl)

VHDL can be used to store a netlist. This format has been added to support simulation of the result with a digital VHDL simulator.

XNF (.xnf)

There is an experimental Xilinx netlist export filter. (ftp://ftp.xilinx.com/pub/documentation/xactstep6/00_index.htm)

Tools

dgc

dgc is the main tool of the package. It creates a netlist from the specified input file.

simfsm

simfsm is a program to generate support files for fsm simulation. Its main purpose is to generate stimuli data for finite state machines. At the moment, only VHDL is supported.

bms2kiss

bms2kiss converts a BMS description into the corresponding KISS description.

dgsop

The dgc package contains many functions for 2-level boolean minimization and manipulation. This tool gives access to some of these functions. The idea of dgsop is to provide a clone of the program ESPRESSO.