The VHDL Enumerator (enm)

The VHDL Enumerator is invoked from the VHDL Environment and is applicable to all non-generated enumeration files which have (usually) been introduced through:

     TopBar -> Introduce -> New -> VHDL Construct -> Enumeration

with file name ending in _EN , and having file extension .enm .

Overview

The enumeration machine defines a collection of sets, and the VHDL enumerator generates a package of functions ( _PK ) for finding the position ( _POS ) of a an element in a set, and one for for finding the value ( _VAL ) of an element at a particular position. The resulting _PK machines are SEEN in VHDL machines where the functions are needed.

Example

The following enumeration:


    ENUMERATION       example_EN

    SETS              SET1 = {el1,el2,el3}

    END

generates the following package:


    MACHINE          example_PK

    /*  This Package has been generated from Enumeration example_EN */

    SETS             SET1 = { el1, el2, el3 }

    CONSTANTS        SET1_VAL, SET1_POS, SET1_SUCC, SET1_PRED

    PROPERTIES

      SET1_VAL = { 0|->el1, 1|->el2, 2|->el3 } &

      SET1_POS = SET1_VAL~ &

      SET1_SUCC = { el1|->el2, el2|->el3 } &

      SET1_PRED = SET1_SUCC~

    END

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