patch no. 16 by Thomy add a function cm_get_circuit to allow accessing the circuit structure ckt from within an XSPICE code model. This is a change to the interface and requires recopiling all code models!

src/include/ngspice/cmproto.h

@@ -48,6 +48,7 @@ NON-STANDARD FEATURES
 
 #include  <stdio.h>
 #include "ngspice/cmtypes.h"
+#include "ngspice/cktdefs.h"
 
 
 void cm_climit_fcn(double in, double in_offset, double cntl_upper, 
@@ -102,6 +103,7 @@ Complex_t cm_complex_multiply(Complex_t x, Complex_t y);
 Complex_t cm_complex_divide(Complex_t x, Complex_t y);
 
 char *cm_get_path(void);
+CKTcircuit *cm_get_circuit(void);
 
 FILE *cm_stream_out(void);
 FILE *cm_stream_in(void);

src/include/ngspice/dllitf.h

@@ -64,6 +64,7 @@ struct coreInfo_t {
 	Complex_t ((*dllitf_cm_complex_multiply)(Complex_t, Complex_t));
 	Complex_t ((*dllitf_cm_complex_divide)(Complex_t, Complex_t));
 	char *    ((*dllitf_cm_get_path)(void));
+	CKTcircuit *((*dllitf_cm_get_circuit)(void));
 	FILE *    ((*dllitf_cm_stream_out)(void));
 	FILE *    ((*dllitf_cm_stream_in)(void));
 	FILE *    ((*dllitf_cm_stream_err)(void));

src/xspice/cm/cm.c

@@ -37,6 +37,7 @@ INTERFACES
     cm_message_get_errmsg()
     cm_message_send()
     cm_get_path()
+    cm_get_circuit()
 
 REFERENCED FILES
 
@@ -706,3 +707,21 @@ char *cm_get_path(void)
     return Infile_Path;
 }
 
+
+/* cm_get_circuit(void)
+
+To build complex custom-built xspice-models, access to certain
+parameters (e.g. maximum step size) may be needed to get reasonable
+results of a simulation. In detail, this may be necessary when
+spice interacts with an external sensor-simulator and the results
+of that external simulator do not have a direct impact on the spice
+circuit. Then, modifying the maximum step size on the fly may help
+to improve the simulation results. Modifying such parameters has to
+be done carefully. The patch enhances the xspice interface with
+access to the (fundamental) ckt pointer.
+*/
+
+CKTcircuit *cm_get_circuit(void)
+{
+    return(g_mif_info.ckt);
+}

src/xspice/cm/cmexport.c

@@ -64,6 +64,7 @@ struct coreInfo_t  coreInfo =
   cm_complex_multiply,
   cm_complex_divide,
   cm_get_path,
+  cm_get_circuit,
   no_file,
   no_file,
   no_file,

src/xspice/icm/dlmain.c

@@ -366,6 +366,10 @@ char * cm_get_path(void) {
 	return (coreitf->dllitf_cm_get_path)();
 }
 
+CKTcircuit *cm_get_circuit(void) {
+	return (coreitf->dllitf_cm_get_circuit)();
+}
+
 FILE * cm_stream_out(void) {
 	return (coreitf->dllitf_cm_stream_out)();
 }

src/xspice/xspice.c

@@ -62,6 +62,7 @@ struct coreInfo_t  coreInfo =
   cm_complex_multiply,
   cm_complex_divide,
   cm_get_path,
+  cm_get_circuit,
   no_file,
   no_file,
   no_file,