/*.......1.........2.........3.........4.........5.........6.........7.........8 ================================================================================ FILE d_dff/cfunc.mod Copyright 1991 Georgia Tech Research Corporation, Atlanta, Ga. 30332 All Rights Reserved PROJECT A-8503-405 AUTHORS 19 June 1991 Jeffrey P. Murray MODIFICATIONS 8 Aug 1991 Jeffrey P. Murray 27 Sep 1991 Jeffrey P. Murray 29 Jan 1992 Jeffrey P. Murray SUMMARY This file contains the functional description of the d_dff 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 ===*/ /*============================================================================== 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_dff() AUTHORS 19 June 1991 Jeffrey P. Murray MODIFICATIONS 8 Aug 1991 Jeffrey P. Murray 27 Sep 1991 Jeffrey P. Murray 29 Jan 1992 Jeffrey P. Murray SUMMARY This function implements the d_dff 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_DFF ROUTINE ===*/ /************************************************ * The following is the model for the * * digital d-type flip flop for the * * ATESSE Version 2.0 system. * * * * Created 6/19/91 J.P.Murray * ************************************************/ void cm_d_dff(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 */ temp; /* temp storage for state values */ /*** Setup required state variables ***/ if(INIT) { /* initial pass */ /* allocate storage */ cm_event_alloc(0,sizeof(Digital_State_t)); cm_event_alloc(1,sizeof(Digital_State_t)); cm_event_alloc(2,sizeof(Digital_State_t)); cm_event_alloc(3,sizeof(Digital_State_t)); /* declare load values */ LOAD(data) = PARAM(data_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) { /****** Initial conditions...output w/o delays ******/ temp = (Digital_State_t) 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; } } } else { if (*out_old != UNKNOWN) { /* set will change output */ /* output goes to UNKNOWN */ *out = UNKNOWN; if ( !PORT_NULL(out) ) { OUTPUT_STATE(out) = UNKNOWN; OUTPUT_DELAY(out) = PARAM(set_delay); } if ( !PORT_NULL(Nout) ) { OUTPUT_STATE(Nout) = UNKNOWN; OUTPUT_DELAY(Nout) = PARAM(set_delay); } } else { *out = *out_old; /* output already unknown */ if ( !PORT_NULL(out) ) { OUTPUT_CHANGED(out) = FALSE; } if ( !PORT_NULL(Nout) ) { OUTPUT_CHANGED(Nout) = FALSE; } } } break; case ZERO: if ( ONE != *reset) { /* output remains at current value */ *out = *out_old; if ( !PORT_NULL(out) ) { OUTPUT_CHANGED(out) = FALSE; } if ( !PORT_NULL(Nout) ) { OUTPUT_CHANGED(Nout) = FALSE; } } else { if (*out_old != ZERO) { /* set will change output */ /* output returns to reset condition */ *out = ZERO; if ( !PORT_NULL(out) ) { OUTPUT_STATE(out) = ZERO; OUTPUT_DELAY(out) = PARAM(set_delay); } if ( !PORT_NULL(Nout) ) { OUTPUT_STATE(Nout) = ONE; OUTPUT_DELAY(Nout) = PARAM(set_delay); } } else { *out = *out_old; /* output already reset */ if ( !PORT_NULL(out) ) { OUTPUT_CHANGED(out) = FALSE; } if ( !PORT_NULL(Nout) ) { OUTPUT_CHANGED(Nout) = FALSE; } } } break; case UNKNOWN: if ( ONE == *reset ) { /* output goes to ZERO */ *out = ZERO; if ( !PORT_NULL(out) ) { OUTPUT_STATE(out) = ZERO; OUTPUT_DELAY(out) = PARAM(set_delay); } if ( !PORT_NULL(Nout) ) { OUTPUT_STATE(Nout) = ONE; OUTPUT_DELAY(Nout) = PARAM(set_delay); } } else { *out = *out_old; /* output already unknown */ if ( !PORT_NULL(out) ) { OUTPUT_CHANGED(out) = FALSE; } if ( !PORT_NULL(Nout) ) { OUTPUT_CHANGED(Nout) = FALSE; } } break; } } else { /**** Test reset value for change ****/ if ( *reset != *reset_old ) { /* either reset or reset release */ switch ( *reset ) { case ONE: if ( ONE != *set) { if (*out_old != ZERO) { /* reset will change output */ /* output goes to ZERO */ *out = ZERO; if ( !PORT_NULL(out) ) { OUTPUT_STATE(out) = ZERO; OUTPUT_DELAY(out) = PARAM(reset_delay); } if ( !PORT_NULL(Nout) ) { OUTPUT_STATE(Nout) = ONE; OUTPUT_DELAY(Nout) = PARAM(reset_delay); } } else { *out = *out_old; /* output already reset */ if ( !PORT_NULL(out) ) { OUTPUT_CHANGED(out) = FALSE; } if ( !PORT_NULL(Nout) ) { OUTPUT_CHANGED(Nout) = FALSE; } } } else { if (*out_old != UNKNOWN) { /* reset will change output */ /* output goes to UNKNOWN */ *out = UNKNOWN; if ( !PORT_NULL(out) ) { OUTPUT_STATE(out) = UNKNOWN; OUTPUT_DELAY(out) = PARAM(reset_delay); } if ( !PORT_NULL(Nout) ) { OUTPUT_STATE(Nout) = UNKNOWN; OUTPUT_DELAY(Nout) = PARAM(reset_delay); } } else { *out = *out_old; /* output already unknown */ if ( !PORT_NULL(out) ) { OUTPUT_CHANGED(out) = FALSE; } if ( !PORT_NULL(Nout) ) { OUTPUT_CHANGED(Nout) = FALSE; } } } break; case ZERO: if ( ONE != *set) { /* output remains at current value */ *out = *out_old; if ( !PORT_NULL(out) ) { OUTPUT_CHANGED(out) = FALSE; } if ( !PORT_NULL(Nout) ) { OUTPUT_CHANGED(Nout) = FALSE; } } else { if (*out_old != ONE) { /* reset will change output */ /* output returns to set condition */ *out = ONE; if ( !PORT_NULL(out) ) { OUTPUT_STATE(out) = ONE; OUTPUT_DELAY(out) = PARAM(reset_delay); } if ( !PORT_NULL(Nout) ) { OUTPUT_STATE(Nout) = ZERO; OUTPUT_DELAY(Nout) = PARAM(reset_delay); } } else { *out = *out_old; /* output already reset */ if ( !PORT_NULL(out) ) { OUTPUT_CHANGED(out) = FALSE; } if ( !PORT_NULL(Nout) ) { OUTPUT_CHANGED(Nout) = FALSE; } } } break; case UNKNOWN: if ( ONE == *set ) { /* output goes to ONE */ *out = ONE; if ( !PORT_NULL(out) ) { OUTPUT_STATE(out) = ONE; OUTPUT_DELAY(out) = PARAM(reset_delay); } if ( !PORT_NULL(Nout) ) { OUTPUT_STATE(Nout) = ZERO; OUTPUT_DELAY(Nout) = PARAM(reset_delay); } } else { *out = *out_old; /* output already unknown */ if ( !PORT_NULL(out) ) { OUTPUT_CHANGED(out) = FALSE; } if ( !PORT_NULL(Nout) ) { OUTPUT_CHANGED(Nout) = FALSE; } } break; } } else { /**** Test clk value for change ****/ if ( (*clk != *clk_old) && (*reset != ONE) && (*set != ONE) ) { /* clock or clock release */ switch ( *clk ) { case ONE: /* active edge...save current data value */ temp = INPUT_STATE(data); if (*out_old != temp) { /* clk will change output */ *out = temp; if ( !PORT_NULL(out) ) { OUTPUT_STATE(out) = temp; OUTPUT_DELAY(out) = PARAM(clk_delay); } cm_toggle_bit(&temp); if ( !PORT_NULL(Nout) ) { OUTPUT_STATE(Nout) = temp; OUTPUT_DELAY(Nout) = PARAM(clk_delay); } } else { *out = *out_old; /* output same as before */ if ( !PORT_NULL(out) ) { OUTPUT_CHANGED(out) = FALSE; } if ( !PORT_NULL(Nout) ) { OUTPUT_CHANGED(Nout) = FALSE; } } break; case ZERO: case UNKNOWN: /* inactive edge...return previous values */ *out = *out_old; if ( !PORT_NULL(out) ) { OUTPUT_CHANGED(out) = FALSE; } if ( !PORT_NULL(Nout) ) { OUTPUT_CHANGED(Nout) = FALSE; } break; } } else { /* data value must have changed... return previous output value. */ *out = *out_old; if ( !PORT_NULL(out) ) { OUTPUT_CHANGED(out) = FALSE; } if ( !PORT_NULL(Nout) ) { OUTPUT_CHANGED(Nout) = FALSE; } } } } /***** Add additional rise or fall delays, if appropriate *****/ if ( *out != *out_old ) { /*** output value is changing ***/ switch ( *out ) { /** fall to zero value **/ case 0: if ( !PORT_NULL(out) ) { OUTPUT_DELAY(out) += PARAM(fall_delay); } if ( !PORT_NULL(Nout) ) { OUTPUT_DELAY(Nout) += PARAM(rise_delay); } break; /** rise to one value **/ case 1: if ( !PORT_NULL(out) ) { OUTPUT_DELAY(out) += PARAM(rise_delay); } if ( !PORT_NULL(Nout) ) { OUTPUT_DELAY(Nout) += PARAM(fall_delay); } break; /** unknown output **/ default: /* based on old value, add rise or fall delay */ if (0 == *out_old) { /* add rising delay */ if ( !PORT_NULL(out) ) { OUTPUT_DELAY(out) += PARAM(rise_delay); } if ( !PORT_NULL(Nout) ) { OUTPUT_DELAY(Nout) += PARAM(fall_delay); } } else { /* add falling delay */ if ( !PORT_NULL(out) ) { OUTPUT_DELAY(out) += PARAM(fall_delay); } if ( !PORT_NULL(Nout) ) { OUTPUT_DELAY(Nout) += PARAM(rise_delay); } } break; } } } /*** output strength values ***/ if ( !PORT_NULL(out) ) { OUTPUT_STRENGTH(out) = STRONG; } if ( !PORT_NULL(Nout) ) { OUTPUT_STRENGTH(Nout) = STRONG; } }