WOLFRAM SYSTEMMODELER

Digital

Library for digital electrical components based on the VHDL standard with 9-valued logic and conversion to 2-,3-,4-valued logic

Package Contents

UsersGuide

User's Guide

Examples

Examples that demonstrate the usage of the Digital electrical components

Interfaces

Basic definitions

Tables

Truth tables for all components of package Digital

Delay

Delay blocks

Basic

Basic logic blocks without delays

Gates

Logic gates including delays

Sources

Time-dependent digital signal sources

Converters

Converters between 2-,3-,4- and 9-valued logic

Registers

Registers with N-bit input data and output data

Tristates

Transfergates, Buffers, Inverters, and WiredX

Memories

Multiplexers

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

This library contains packages for digital electrical components. Both, type system and models are based on the VHDL standard (IEEE Std 1076-1987 VHDL, IEEE Std 1076-1993 VHDL, IEEE Std 1164 Multivalue Logic System):

  • Interfaces: Definition of signals and interfaces
  • Tables: All truth tables needed
  • Delay: Transport and inertial delay
  • Basic: Basic logic without delay
  • Gates: Basic gates composed by basic components and inertial delay
  • Tristate: (not yet available)
  • FlipFlops: D-Flip-Flops
  • Latches: D-Latches
  • TransferGates: (not yet available)
  • Multiplexers (not yet available)
  • Memory: Ram, Rom, (not yet available)
  • Sources: Time-dependent signal sources
  • Converters
  • Examples

The logic values are coded by integer values. The following code table is necessary for both setting of input and interpreting the output values.

Code Table:

Logic value Integer code Meaning
'U' 1 Uninitialized
'X' 2 Forcing Unknown
'0' 3 Forcing 0
'1' 4 Forcing 1
'Z' 5 High Impedance
'W' 6 Weak Unknown
'L' 7 Weak 0
'H' 8 Weak 1
'-' 9 Do not care

The library will be developed in two main steps. The first step contains the basic components and the gates. In the next step the more complicated devices will be added. Currently the first step of the library is implemented and released for public use.

Copyright © 1998-2013, Modelica Association and Fraunhofer-Gesellschaft.

This Modelica package is free software and the use is completely at your own risk; it can be redistributed and/or modified under the terms of the Modelica License 2. For license conditions (including the disclaimer of warranty) see Modelica.UsersGuide.ModelicaLicense2 or visit https://www.modelica.org/licenses/ModelicaLicense2.