Package Modelica.​Electrical.​Digital
Library for digital electrical components based on the VHDL standard with 9-valued logic and conversion to 2-,3-,4-valued logic


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):

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 © 1998-2019, Modelica Association and contributors

Extends from Modelica.​Icons.​Package (Icon for standard packages).

Package Contents

BasicBasic logic blocks without delays
ConvertersConverters between 2-,3-,4- and 9-valued logic
DelayDelay blocks
ExamplesExamples that demonstrate the usage of the Digital electrical components
GatesLogic gates including delays
InterfacesBasic definitions
RegistersRegisters with N-bit input data and output data
SourcesTime-dependent digital signal sources
TablesTruth tables for all components of package Digital
TristatesTransfergates, Buffers, Inverters, and WiredX
UsersGuideUser's Guide