From f073fb5c0555d1202c32e5905946190a9920c914 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Fri, 8 Jul 2022 09:31:07 +0200
Subject: [PATCH] Consecutive tran and ac simulation may lead to gross errors
 when TC or scale is used on the instance line of C and L. Reason is the
 missing reset when CKTtemp is called once during each simulation command. TC
 or scale is then applied again and again, a reset is missing.

This patch adds a reset, i.e. the capacitance or inductance is
reset to its instance value in a call to *temp. It fixes bug#594.

Command 'alter' has been tested.

Resistance has not been tackled by this bug, because the line
here->RESconduct = here->RESm / (here->RESresist * factor * here->RESscale);
differs from
here->CAPcapac = here->CAPcapac * factor * here->CAPscale;
in that there is no accumulation of correction factors with here->RESconduct
---
 src/spicelib/devices/cap/capdefs.h  | 1 +
 src/spicelib/devices/cap/capparam.c | 2 +-
 src/spicelib/devices/cap/captemp.c  | 9 ++++++---
 src/spicelib/devices/ind/inddefs.h  | 1 +
 src/spicelib/devices/ind/indparam.c | 2 +-
 src/spicelib/devices/ind/indtemp.c  | 3 +++
 6 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/spicelib/devices/cap/capdefs.h b/src/spicelib/devices/cap/capdefs.h
index b7c0e5854..1b188ceda 100644
--- a/src/spicelib/devices/cap/capdefs.h
+++ b/src/spicelib/devices/cap/capdefs.h
@@ -33,6 +33,7 @@ typedef struct sCAPinstance {
     double CAPtemp;     /* temperature at which this capacitor operates */
     double CAPdtemp;    /* delta-temperature of this instance */
     double CAPcapac;    /* capacitance */
+    double CAPcapacinst;/* capacitance on instance line */
     double CAPinitCond; /* initial capacitor voltage if specified */
     double CAPwidth;    /* width of the capacitor */
     double CAPlength;   /* length of the capacitor */
diff --git a/src/spicelib/devices/cap/capparam.c b/src/spicelib/devices/cap/capparam.c
index 0e030ceef..ea5ca9f35 100644
--- a/src/spicelib/devices/cap/capparam.c
+++ b/src/spicelib/devices/cap/capparam.c
@@ -29,7 +29,7 @@ CAPparam(int param, IFvalue *value, GENinstance *inst, IFvalue *select)
 
     switch(param) {
     case CAP_CAP:
-        here->CAPcapac = value->rValue;
+        here->CAPcapacinst = here->CAPcapac = value->rValue;
         if (!here->CAPmGiven)
             here->CAPm = 1.0;
         here->CAPcapGiven = TRUE;
diff --git a/src/spicelib/devices/cap/captemp.c b/src/spicelib/devices/cap/captemp.c
index 926a3c666..319188f07 100644
--- a/src/spicelib/devices/cap/captemp.c
+++ b/src/spicelib/devices/cap/captemp.c
@@ -52,7 +52,7 @@ CAPtemp(GENmodel *inModel, CKTcircuit *ckt)
             if (!here->CAPscaleGiven) here->CAPscale = 1.0;
             if (!here->CAPmGiven)     here->CAPm     = 1.0;
 
-            if (!here->CAPcapGiven)  { /* No instance capacitance given */
+            if (!here->CAPcapGiven) { /* No instance capacitance given */
                 if (!model->CAPmCapGiven) { /* No model capacitange given */
                     here->CAPcapac =
                         model->CAPcj *
@@ -60,11 +60,14 @@ CAPtemp(GENmodel *inModel, CKTcircuit *ckt)
                         (here->CAPlength - model->CAPshort) +
                         model->CAPcjsw * 2 * (
                             (here->CAPlength - model->CAPshort) +
-                            (here->CAPwidth - model->CAPnarrow) );
-                } else {
+                            (here->CAPwidth - model->CAPnarrow));
+                }
+                else {
                     here->CAPcapac = model->CAPmCap;
                 }
             }
+            else
+                here->CAPcapac = here->CAPcapacinst; /* reset capacitance to instance value */
 
             difference = (here->CAPtemp + here->CAPdtemp) - model->CAPtnom;
 
diff --git a/src/spicelib/devices/ind/inddefs.h b/src/spicelib/devices/ind/inddefs.h
index f39d152ed..41ef790de 100644
--- a/src/spicelib/devices/ind/inddefs.h
+++ b/src/spicelib/devices/ind/inddefs.h
@@ -36,6 +36,7 @@ struct sINDinstance {
 
     int INDbrEq;    /* number of the branch equation added for current */
     double INDinduct;    /* inductance */
+    double INDinductinst;/* inductance on instance line */
     double INDm;         /* Parallel multiplier */
     double INDtc1;       /* first temperature coefficient of resistors */
     double INDtc2;       /* second temperature coefficient of resistors */
diff --git a/src/spicelib/devices/ind/indparam.c b/src/spicelib/devices/ind/indparam.c
index e39584c6f..23f776dcf 100644
--- a/src/spicelib/devices/ind/indparam.c
+++ b/src/spicelib/devices/ind/indparam.c
@@ -22,7 +22,7 @@ INDparam(int param, IFvalue *value, GENinstance *inst, IFvalue *select)
 
     switch(param) {
     case IND_IND:
-        here->INDinduct = value->rValue;
+        here->INDinductinst = here->INDinduct = value->rValue;
         if (!here->INDmGiven)
             here->INDm =1.0;
         here->INDindGiven = TRUE;
diff --git a/src/spicelib/devices/ind/indtemp.c b/src/spicelib/devices/ind/indtemp.c
index c355e03d8..40149955b 100644
--- a/src/spicelib/devices/ind/indtemp.c
+++ b/src/spicelib/devices/ind/indtemp.c
@@ -52,6 +52,9 @@ INDtemp(GENmodel *inModel, CKTcircuit *ckt)
                 else
                     here->INDinduct = model->INDmInd;
             }
+            else
+                here->INDinduct = here->INDinductinst; /* reset inductance to instance value */
+
             difference = (here->INDtemp + here->INDdtemp) - model->INDtnom;
 
             /* instance parameters tc1 and tc2 will override