NAME

       PAT - Generic pattern data structure

DESCRIPTION

       PAT  is  a  generic  data  structure supporting vlsi concepts.  It allows representation of a sequence of
       simulation patterns in a data structure.

       The goal of PAT is to define an ad hoc single data structure (object), with well known fixed meaning  for
       each  concept  manipulated  in pattern description. So any tools that needs to access simulation patterns
       can be build upon it, using these structures.

       For each object (data structure), a set of functions has been defined in order to add, delete  or  access
       it.  These  functions  are  defined  in  a low-level library libPat106.a. Some other functions are higher
       level. They are defined in a high-level library libPhl106.a. There  are  also  some  parsers-drivers.   A
       parser reads a pattern description file in a given format and build up a complete PAT data base. A driver
       creates a text file in a given format from a PAT data base. A pat format parser-driver  is  available  in
       the libPpt106.a library.

       Pattern description envolves the following notions (for further details see pat(5)):

       input               port controlled by the user

       output              signal or port observed by the user

       initialization      forcing the value of a register

       pattern sequence    list  of  values  to  be  forced  on  inputs  or  to  be checked as the result of the
                           simulation on outputs

       The input-output list is represented by two data structures:  pagrp  contains  informations  relative  to
       actual  or  virtual  arraies and, paiol represents a one-bit input-output. Both are simply chained lists.
       However, to make a more efficient access to paiol structures, they are organized in a table. So, a  paiol
       can also be addressed using an offset.

       Another  group of data structures is used to represent a pattern. paini contains values to be forced into
       registers before processing the pattern.  An event (a modification of value) on an input-output is  given
       by  a  paevt  structure. A third structure, papat gathers all information concerning a pattern (including
       initializations - paini - and events - paevt).

       A pacom is used to represent a comment.

       Finally, all these structures can be accessed through a unique structure, paseq, designed to represent  a
       complete sequence of simulation patterns.

ORGANIZATION

       In  order  to  use  PAT,  concepts  on  use of libraries are needed. And, since these libraries are under
       development, the code is subject to change.

       To enable work, a static version of each library is always present for the  user.  Libraries  and  header
       files are suffixed by a number (the library's version). The programmer can prefer to work with an earlier
       version of a library rather than the most recent one. However, it is recommended to  adapt  softwares  to
       libraries as soon as possible in order to spotlight potential compatibility problems before old libraries
       are removed.

       A makefile is necessary for all PAT applications.  This is required  because  any  soft  must  be  easily
       recompilable,  and  knowing the needed libraries for a PAT based program is not an easy matter.  It can't
       be achieved by an other way, so do use makefile.

       In terms of software organization, PAT is splitted into two libraries for the basic functions,  a  header
       file for structures and variable declarations and, up to now, one parser-driver library for pat format.

       It  is  to be noticed that library's version number is incremented when, at least, one function composing
       the library has been modified. Therefore, PAT libraries may evolve independently form each other.

       Here follows the list of the libraries and their contents.

       libPat106.a:        pat_addpaseq,  pat_addpagrp,                             pat_addpaiol,  pat_addpapat,
                           pat_addpaevt,  pat_addpaini,                             pat_addpacom,  pat_frepaini,
                           pat_frepaiol,  pat_frepacom, pat_frepapat,  pat_frepaevt, pat_crtpaiol

       libPhl106.a:        pat_debug,     pat_getcount

       libPpt106.a:        pat_lodpaseq,  pat_savpaseq, pat_drvpat,    pat_prspat

       The libraries are organized in such a way that no cycle can appear through calls. It means that, if in  a
       given  library  a  function calls another function in another library, then none of the functions of this
       one does call any function that belongs to the first library.

EXAMPLE

       In order to use PAT libraries, one needs something like this in its makefile:

              HEADER = -I/labo/include
              LIB = -L/labo/lib -lPat106 -lPhl106 -lPpt106 -lMut315

SEE ALSO

       mbk(1), pat(5)