cfunc.mod

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/* $Id: cfunc.mod,v 1.4 2005/08/23 08:21:01 pnenzi Exp $ */
/*.......1.........2.........3.........4.........5.........6.........7.........8
================================================================================

FILE d_tff/cfunc.mod

Copyright 1991
Georgia Tech Research Corporation, Atlanta, Ga. 30332
All Rights Reserved

PROJECT A-8503-405
               

AUTHORS                      

   24 June 1991     Jeffrey P. Murray


MODIFICATIONS   

    12 Aug 1991    Jeffrey P. Murray
     2 Oct 1991    Jeffrey P. Murray
    29 Jan 1992    Jeffrey P. Murray
                                   

SUMMARY

    This file contains the model-specific routines used to
    functionally describe the d_tff code model.


INTERFACES       

    FILE                 ROUTINE CALLED     

    CMutil.c             void cm_toggle_bit(); 

    CMevt.c              void *cm_event_alloc()
                         void *cm_event_get_ptr()


REFERENCED FILES

    Inputs from and outputs to ARGS structure.
                     

NON-STANDARD FEATURES

    NONE

===============================================================================*/

/*=== INCLUDE FILES ====================*/


                                      

/*=== CONSTANTS ========================*/




/*=== MACROS ===========================*/



  
/*=== LOCAL VARIABLES & TYPEDEFS =======*/                         


    
           
/*=== FUNCTION PROTOTYPE DEFINITIONS ===*/




                   
/*=============================================================================*/

/*=== CM<model_name> ROUTINE ===*/




/*==============================================================================

FUNCTION cm_toggle_bit()


AUTHORS                      

    27 Sept 1991     Jeffrey P. Murray


MODIFICATIONS   

    NONE


SUMMARY

    Alters the state of a passed digital variable to its
    complement. Thus, a ONE changes to a ZERO. A ZERO changes
    to a ONE, and an UNKNOWN remains unchanged.


INTERFACES       

    FILE                 ROUTINE CALLED     

    N/A                  N/A


RETURNED VALUE
    
    No returned value. Passed pointer to variable is used 
    to redefine the variable value.
           

GLOBAL VARIABLES
    
    NONE


NON-STANDARD FEATURES

    NONE
                                                   
/*=============================================================================*/

/*=== CM_TOGGLE_BIT ROUTINE ===*/

static void cm_toggle_bit(Digital_State_t *bit) 

{
    /* Toggle bit from ONE to ZERO or vice versa, unless the
       bit value is UNKNOWN. In the latter case, return 
       without changing the bit value.                      */

    if ( UNKNOWN != *bit ) {
        if ( ONE == *bit ) {
            *bit = ZERO;
        }
        else { 
            *bit = ONE;
        }
    }

}


                   
/*==============================================================================

FUNCTION cm_d_tff()


AUTHORS                      

    24 Jun 1991     Jeffrey P. Murray


MODIFICATIONS   

    29 Jan 1992     Jeffrey P. Murray


SUMMARY

    This function implements the d_tff code model.


INTERFACES       

    FILE                 ROUTINE CALLED     

    CMutil.c             void cm_toggle_bit(); 

    CMevt.c              void *cm_event_alloc()
                         void *cm_event_get_ptr()



RETURNED VALUE
    
    Returns inputs and outputs via ARGS structure.
           

GLOBAL VARIABLES
    
    NONE


NON-STANDARD FEATURES

    NONE
                                                   
/*=============================================================================*/

/*=== CM_D_TFF ROUTINE ===*/

/************************************************
*      The following is the model for the       *
*   digital t-type flip flop for the            *
*   ATESSE Version 2.0 system.                  *
*                                               *
*   Created 6/24/91               J.P.Murray    *
************************************************/


void cm_d_tff(ARGS) 

{
    /*int                    i;*/   /* generic loop counter index */
                        

    Digital_State_t     *clk,   /* current clk value    */
                    *clk_old,   /* previous clk value   */
                        *set,   /* current set value for dff    */
                    *set_old,   /* previous set value for dff   */
                      *reset,   /* current reset value for dff      */
                  *reset_old,   /* previous reset value for dff     */
                        *out,   /* current output for dff   */
                    *out_old,   /* previous output for dff  */                            

                toggle_input,   /* current toggle input value    */                            

                        temp;   /* temp storage for state values    */                            



    /*** Setup required state variables ***/

    if(INIT) {  /* initial pass */ 

        /* allocate storage */
        clk = clk_old = (Digital_State_t *) cm_event_alloc(0,sizeof(Digital_State_t));
        set = set_old = (Digital_State_t *) cm_event_alloc(1,sizeof(Digital_State_t));
        reset = reset_old = (Digital_State_t *) cm_event_alloc(2,sizeof(Digital_State_t));
        out = out_old = (Digital_State_t *) cm_event_alloc(3,sizeof(Digital_State_t));

        /* declare load values */
        LOAD(t) = PARAM(t_load);
        LOAD(clk) = PARAM(clk_load);
        if ( !PORT_NULL(set) ) {
            LOAD(set) = PARAM(set_load);
        }
        if ( !PORT_NULL(reset) ) {
        LOAD(reset) = PARAM(reset_load);
        }

        /* retrieve storage for the outputs */
        clk = clk_old = (Digital_State_t *) cm_event_get_ptr(0,0);
        set = set_old = (Digital_State_t *) cm_event_get_ptr(1,0);
        reset = reset_old = (Digital_State_t *) cm_event_get_ptr(2,0);
        out = out_old = (Digital_State_t *) cm_event_get_ptr(3,0);

    }
    else {      /* Retrieve previous values */
                                              
        /* retrieve storage for the outputs */
        clk = (Digital_State_t *) cm_event_get_ptr(0,0);
        clk_old = (Digital_State_t *) cm_event_get_ptr(0,1);
        set = (Digital_State_t *) cm_event_get_ptr(1,0);
        set_old = (Digital_State_t *) cm_event_get_ptr(1,1);
        reset = (Digital_State_t *) cm_event_get_ptr(2,0);
        reset_old = (Digital_State_t *) cm_event_get_ptr(2,1);
        out = (Digital_State_t *) cm_event_get_ptr(3,0);
        out_old = (Digital_State_t *) cm_event_get_ptr(3,1);
    }



    /******** load current input values if set or reset 
              are not connected, set to zero... ********/
    *clk = INPUT_STATE(clk);
    if ( PORT_NULL(set) ) {
        *set = *set_old = ZERO;
    }
    else {
        *set = INPUT_STATE(set);
    }
    if ( PORT_NULL(reset) ) {
        *reset = *reset_old = ZERO;
    }
    else {
        *reset = INPUT_STATE(reset);
    }



         
                            

    /******* Determine analysis type and output appropriate values *******/

    if (0.0 == TIME) {   /****** DC analysis...output w/o delays ******/
                                                            
         temp = PARAM(ic);

        /** Modify output if set or reset lines are active **/
        if ( (*set==ONE) && (*reset==ZERO) ) temp = ONE;
        if ( (*set==ZERO) && (*reset==ONE) ) temp = ZERO;
        if ( (*set==ONE) && (*reset==ONE) ) temp = UNKNOWN;

        *out = *out_old = temp;


        if ( !PORT_NULL(out) ) {
            OUTPUT_STATE(out) = temp;
        }

        cm_toggle_bit(&temp);

        if ( !PORT_NULL(Nout) ) {
            OUTPUT_STATE(Nout) = temp;
        }
    }

    else {      /****** Transient Analysis ******/


        /***** Find input that has changed... *****/

        /**** Test set value for change ****/
        if ( *set != *set_old ) { /* either set or set release */
            switch ( *set ) {

            case ONE:
                if ( ONE != *reset) {
                    if (*out_old != ONE) {  /* set will change output */
                        /* output goes to ONE */
                        *out = ONE;

                        if ( !PORT_NULL(out) ) {
                            OUTPUT_STATE(out) = ONE;
                            OUTPUT_DELAY(out) = PARAM(set_delay);
                        }
                        if ( !PORT_NULL(Nout) ) {
                            OUTPUT_STATE(Nout) = ZERO;
                            OUTPUT_DELAY(Nout) = PARAM(set_delay);
                        }
                    }
                    else {
                        *out = *out_old;     /* output already set */
                        if ( !PORT_NULL(out) ) {
                            OUTPUT_CHANGED(out) = FALSE;
                        }
                        if ( !PORT_NULL(Nout) ) {
                            OUTPUT_CHANGED(Nout) = FALSE;
                        }
                    }