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Function add_degmodel() adds the degradation model to the netlist 

Add a 0 voltage source between internal and external source for
current measurement.
Add a B source parallel to drain and source for current reduction.
Use the mean of d_idlin (result[1]) and d_idsat (result[2])
as proportional factor to current.
Add a voltage source between external and internal gate
to apply dlt_vth shift from result[0]
This commit is contained in:
Holger Vogt 2026-02-13 16:59:06 +01:00
parent 53aa1f991e
commit 9e97aac1dd
1 changed files with 47 additions and 1 deletions
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48
src/frontend/inpdeg.c
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@ -16,6 +16,7 @@ License: Modified BSD
#include "inpcom.h"
int prepare_degsim(struct card* deck);
static int add_degmodel(struct card* deck, double* result);
/* maximum number of model parameters */
#define DEGPARAMAX 64
@ -330,12 +331,17 @@ int prepare_degsim(struct card* deck) {
}
/* get the device instance line */
insttoken = gettok_instance(&prevline);
if (*insttoken != 'n' && *insttoken != 'm'){
fprintf(stderr, "Error: expected N or M device, but found %s\n", insttoken);
continue;
}
result = (double*)nghash_find(degdatahash, insttoken);
if (result) {
fprintf(stdout, "Instance %s, Result: %e, %e, %e\n", insttoken, result[0], result[1], result[2]);
add_degmodel(prevcard, result);
}
else
fprintf(stdout, "Instance %s not found in hash table\n", insttoken);
fprintf(stdout, "Instance %s not found in hash table,\n no degradation data available\n", insttoken);
tfree(insttoken);
@ -352,3 +358,43 @@ int clear_degsim (void){
/* delete the hashtables */
return 0;
}
/* Add a 0 voltage source between internal and external source for current measurement.
Add a B source parallel to drain and source for current reduction.
Use the mean of d_idlin (result[1]) and d_idsat (result[2]) as proportional factor to current.
Add a voltage source between external and internal gate to apply dlt_vth shift from result[0]. */
static int add_degmodel(struct card* deck, double* result) {
char* dtok, * gtok, * stok, *intok;
char* nline[3]; /* three new lines to be added to netlist */
char* curr_line = deck->line;
intok = gettok_instance(&curr_line); /* skip instance name */
dtok = gettok_node(&curr_line); /* get drain, gate, and source tokens */
gtok = gettok_node(&curr_line);
stok = gettok_node(&curr_line);
if (!dtok || !gtok || !stok) {
fprintf(stderr, "Error: not enough tokens in instance line %s.\n", deck->line);
return 1;
}
/* current measurement*/
nline[0] = tprintf("Vm%s intern_%s %s 0\n", intok, stok, stok);
/* gate voltage shift */
nline[1] = tprintf("Vg%s intern_%s %s %e\n", intok, gtok, gtok, result[0]);
/* parallel drain current */
double currdeg = (result[1] + result[2]) / 2.;
nline[2] = tprintf("B%s %s %s i = i(Vm%s) * %e\n", intok, dtok, stok, intok, currdeg);
/* modify the instance line */
char* instline = tprintf("%s %s intern_%s intern_%s %s\n", intok, dtok, gtok, stok, curr_line);
tfree(deck->line);
deck->line = instline;
/* attach to the netlist */
int ii;
for (ii = 0; ii < 3; ii++) {
insert_new_line(deck, nline[ii], deck->linenum + 1, deck->linenum_orig, deck->linesource);
}
tfree(intok);
tfree(dtok);
tfree(gtok);
tfree(stok);
return 0;
}