alternative geometry correction `del' for semiconductor capacitors

src/spicelib/devices/cap/cap.c

@@ -47,6 +47,7 @@ IFparm CAPmPTable[] = { /* names of model parameters */
     IOPR( "l",      CAP_MOD_DEFLENGTH,IF_REAL, "Default length"),
     IOPA( "narrow", CAP_MOD_NARROW,   IF_REAL, "width correction factor"),
     IOPA( "short",  CAP_MOD_SHORT,    IF_REAL, "length correction factor"),
+    IOPA( "del",    CAP_MOD_DEL,      IF_REAL, "length and width correction factor"),
     IOPA( "tc1",    CAP_MOD_TC1,      IF_REAL, "First order temp. coefficient"),
     IOPA( "tc2",    CAP_MOD_TC2,      IF_REAL, "Second order temp. coefficient"),
     IOPXU("tnom",   CAP_MOD_TNOM,     IF_REAL, "Parameter measurement temperature"),

src/spicelib/devices/cap/capdefs.h

@@ -88,6 +88,7 @@ typedef struct sCAPmodel {      /* model structure for a capacitor */
     double CAPdefLength;  /* the default length of a capacitor */
     double CAPnarrow;     /* amount by which width are less than drawn */
     double CAPshort;      /* amount by which length are less than drawn */
+    double CAPdel;        /* amount by which length and width are less than drawn */
     double CAPdi;         /* Relative dielectric constant */
     double CAPthick;      /* Insulator thickness */
     unsigned CAPmCapGiven      : 1;    /* flag indicates default capacitance given */
@@ -97,6 +98,7 @@ typedef struct sCAPmodel {      /* model structure for a capacitor */
     unsigned CAPdefLengthGiven : 1;    /* flag indicates deafult lenght given */
     unsigned CAPnarrowGiven    : 1;    /* flag indicates narrowing factor given */
     unsigned CAPshortGiven     : 1;    /* flag indicates shortening factor given */
+    unsigned CAPdelGiven       : 1;    /* flag indicates del factor given */
     unsigned CAPtnomGiven      : 1;    /* flag indicates nominal temp. given */
     unsigned CAPtc1Given       : 1;    /* flag indicates tc1 was specified */
     unsigned CAPtc2Given       : 1;    /* flag indicates tc2 was specified */
@@ -127,13 +129,14 @@ typedef struct sCAPmodel {      /* model structure for a capacitor */
 #define CAP_MOD_C 104
 #define CAP_MOD_NARROW 105
 #define CAP_MOD_SHORT 106
-#define CAP_MOD_TC1 107
-#define CAP_MOD_TC2 108
-#define CAP_MOD_TNOM 109
-#define CAP_MOD_DI 110
-#define CAP_MOD_THICK 111
-#define CAP_MOD_CAP 112
-#define CAP_MOD_DEFLENGTH 113
+#define CAP_MOD_DEL 107
+#define CAP_MOD_TC1 108
+#define CAP_MOD_TC2 109
+#define CAP_MOD_TNOM 110
+#define CAP_MOD_DI 111
+#define CAP_MOD_THICK 112
+#define CAP_MOD_CAP 113
+#define CAP_MOD_DEFLENGTH 114
 
 /* device questions */
 #define CAP_QUEST_SENS_REAL      201

src/spicelib/devices/cap/capmask.c

@@ -54,6 +54,9 @@ CAPmAsk(CKTcircuit *ckt, GENmodel *inst, int which, IFvalue *value)
     case CAP_MOD_SHORT:
         value->rValue = here->CAPshort;
         return(OK);
+    case CAP_MOD_DEL:
+        value->rValue = here->CAPdel;
+        return(OK);
     case CAP_MOD_DI:
         value->rValue = here->CAPdi;
         return(OK);

src/spicelib/devices/cap/capmpar.c

@@ -58,6 +58,10 @@ CAPmParam(int param, IFvalue *value, GENmodel *inModel)
         mod->CAPshort = value->rValue;
         mod->CAPshortGiven = TRUE;
         break;
+    case CAP_MOD_DEL:
+        mod->CAPdel = value->rValue;
+        mod->CAPdelGiven = TRUE;
+        break;
     case CAP_MOD_DI:
         mod->CAPdi = value->rValue;
         mod->CAPdiGiven = TRUE;

src/spicelib/devices/cap/capsetup.c

@@ -46,6 +46,9 @@ CAPsetup(SMPmatrix *matrix, GENmodel *inModel, CKTcircuit *ckt, int *states)
         if (!model->CAPshortGiven) {
             model->CAPshort = 0.0;
         }
+        if (!model->CAPdelGiven) {
+            model->CAPdel = 0.0;
+        }
         if (!model->CAPtc1Given) {
             model->CAPtempCoeff1 = 0.0;
         }
@@ -74,6 +77,13 @@ CAPsetup(SMPmatrix *matrix, GENmodel *inModel, CKTcircuit *ckt, int *states)
             }
         }
 
+        if (model->CAPdelGiven) {
+            if (!model->CAPnarrowGiven)
+                model->CAPnarrow = 2 * model->CAPdel;
+            if (!model->CAPshortGiven)
+                model->CAPshort = 2 * model->CAPdel;
+        }
+
         /* loop through all the instances of the model */
         for (here = model->CAPinstances; here != NULL ;
                 here=here->CAPnextInstance) {