/**** BSIM3v3.2.4, Released by Xuemei Xi 12/21/2001 ****/

/**********
 * Copyright 2001 Regents of the University of California. All rights reserved.
 * File: b3noi.c of BSIM3v3.2.4
 * Author: 1995 Gary W. Ng and Min-Chie Jeng.
 * Author: 1997-1999 Weidong Liu.
 * Author: 2001 Xuemei Xi
 * Modified by Xuemei Xi, 10/05, 12/21, 2001.
 * Modified bt Paolo Nenzi 2002 and Dietmar Warning 2003
 **********/

#include "ngspice/ngspice.h"
#include "bsim3v32def.h"
#include "ngspice/cktdefs.h"
#include "ngspice/iferrmsg.h"
#include "ngspice/noisedef.h"
#include "ngspice/suffix.h"
#include "ngspice/const.h"  /* jwan */

/*
 * BSIM3v32noise (mode, operation, firstModel, ckt, data, OnDens)
 *    This routine names and evaluates all of the noise sources
 *    associated with MOSFET's.  It starts with the model *firstModel and
 *    traverses all of its insts.  It then proceeds to any other models
 *    on the linked list.  The total output noise density generated by
 *    all of the MOSFET's is summed with the variable "OnDens".
 */

/*
 Channel thermal and flicker noises are calculated based on the value
 of model->BSIM3v32noiMod.
 If model->BSIM3v32noiMod = 1,
    Channel thermal noise = SPICE2 model
    Flicker noise         = SPICE2 model
 If model->BSIM3v32noiMod = 2,
    Channel thermal noise = BSIM3v32 model
    Flicker noise         = BSIM3v32 model
 If model->BSIM3v32noiMod = 3,
    Channel thermal noise = SPICE2 model
    Flicker noise         = BSIM3v32 model
 If model->BSIM3v32noiMod = 4,
    Channel thermal noise = BSIM3v32 model
    Flicker noise         = SPICE2 model
 */


/*
 * The StrongInversionNoiseEval function has been modified in
 * the release 3.2.4 of BSIM3v32 model. To accomodate both the old
 * and the new code, I have renamed according to the following:
 *
 *
 * BSIM3v3.2.4 -> StrongInversionNoiseEvalNew
 * Previous    -> StrongInversionNoiseEvalOld
 *
 * 2002 Paolo Nenzi
 */

/*
 * JX: 1/f noise model is smoothed out 12/18/01.
 */

static double
StrongInversionNoiseEvalNew(double Vds, BSIM3v32model *model,
                            BSIM3v32instance *here, double freq, double temp)
{
struct bsim3v32SizeDependParam *pParam;
double cd, esat, DelClm, EffFreq, N0, Nl;
double T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, Ssi;

    pParam = here->pParam;
    cd = fabs(here->BSIM3v32cd);
    esat = 2.0 * pParam->BSIM3v32vsattemp / here->BSIM3v32ueff;
    if(model->BSIM3v32em<=0.0) DelClm = 0.0;
    else {
            T0 = ((((Vds - here->BSIM3v32Vdseff) / pParam->BSIM3v32litl)
                    + model->BSIM3v32em) / esat);
            DelClm = pParam->BSIM3v32litl * log (MAX(T0, N_MINLOG));
    }
    EffFreq = pow(freq, model->BSIM3v32ef);
    T1 = CHARGE * CHARGE * 8.62e-5 * cd * temp * here->BSIM3v32ueff;
    T2 = 1.0e8 * EffFreq * here->BSIM3v32Abulk * model->BSIM3v32cox
       * pParam->BSIM3v32leff * pParam->BSIM3v32leff;
    N0 = model->BSIM3v32cox * here->BSIM3v32Vgsteff / CHARGE;
    Nl = model->BSIM3v32cox * here->BSIM3v32Vgsteff
              * (1.0 - here->BSIM3v32AbovVgst2Vtm * here->BSIM3v32Vdseff) / CHARGE;

    T3 = model->BSIM3v32oxideTrapDensityA
       * log(MAX(((N0 + 2.0e14) / (Nl + 2.0e14)), N_MINLOG));
    T4 = model->BSIM3v32oxideTrapDensityB * (N0 - Nl);
    T5 = model->BSIM3v32oxideTrapDensityC * 0.5 * (N0 * N0 - Nl * Nl);

    T6 = 8.62e-5 * temp * cd * cd;
    T7 = 1.0e8 * EffFreq * pParam->BSIM3v32leff
       * pParam->BSIM3v32leff * pParam->BSIM3v32weff;
    T8 = model->BSIM3v32oxideTrapDensityA + model->BSIM3v32oxideTrapDensityB * Nl
       + model->BSIM3v32oxideTrapDensityC * Nl * Nl;
    T9 = (Nl + 2.0e14) * (Nl + 2.0e14);

    Ssi = T1 / T2 * (T3 + T4 + T5) + T6 / T7 * DelClm * T8 / T9;
    return Ssi;
}

/*
 * The code for releases: BSIM3V32, BSIM3V322, BSIM3V323
 * follows
 */

static double
StrongInversionNoiseEvalOld(double vgs, double vds, BSIM3v32model *model,
                            BSIM3v32instance *here, double freq, double temp)
{
  struct bsim3v32SizeDependParam *pParam;
  double cd, esat, DelClm, EffFreq, N0, Nl, Vgst;
  double T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, Ssi;

  pParam = here->pParam;
  cd = fabs (here->BSIM3v32cd);
  /* Added revision dependent code */
  if (model->BSIM3v32intVersion < BSIM3v32V323)
  {
    if (vds > here->BSIM3v32vdsat)
    {
      esat = 2.0 * pParam->BSIM3v32vsattemp / here->BSIM3v32ueff;
      T0 = ((((vds - here->BSIM3v32vdsat) / pParam->BSIM3v32litl) +
             model->BSIM3v32em) / esat);
      DelClm = pParam->BSIM3v32litl * log (MAX (T0, N_MINLOG));
    }
    else
      DelClm = 0.0;
  }
  else
  {
    if (model->BSIM3v32em <= 0.0)        /* flicker noise modified -JX */
      DelClm = 0.0;
    else if (vds > here->BSIM3v32vdsat)
    {
      esat = 2.0 * pParam->BSIM3v32vsattemp / here->BSIM3v32ueff;
      T0 = ((((vds - here->BSIM3v32vdsat) / pParam->BSIM3v32litl) +
             model->BSIM3v32em) / esat);
      DelClm = pParam->BSIM3v32litl * log (MAX (T0, N_MINLOG));
    }
    else
      DelClm = 0.0;
  }
  EffFreq = pow (freq, model->BSIM3v32ef);
  T1 = CHARGE * CHARGE * 8.62e-5 * cd * temp * here->BSIM3v32ueff;
  T2 = 1.0e8 * EffFreq * model->BSIM3v32cox
     * pParam->BSIM3v32leff * pParam->BSIM3v32leff;
  Vgst = vgs - here->BSIM3v32von;
  N0 = model->BSIM3v32cox * Vgst / CHARGE;
  if (N0 < 0.0)
      N0 = 0.0;
  Nl = model->BSIM3v32cox * (Vgst - MIN (vds, here->BSIM3v32vdsat)) / CHARGE;
  if (Nl < 0.0)
      Nl = 0.0;

  T3 = model->BSIM3v32oxideTrapDensityA
     * log (MAX (((N0 + 2.0e14) / (Nl + 2.0e14)), N_MINLOG));
  T4 = model->BSIM3v32oxideTrapDensityB * (N0 - Nl);
  T5 = model->BSIM3v32oxideTrapDensityC * 0.5 * (N0 * N0 - Nl * Nl);

  T6 = 8.62e-5 * temp * cd * cd;
  T7 = 1.0e8 * EffFreq * pParam->BSIM3v32leff
     * pParam->BSIM3v32leff * pParam->BSIM3v32weff;
  T8 = model->BSIM3v32oxideTrapDensityA + model->BSIM3v32oxideTrapDensityB * Nl
     + model->BSIM3v32oxideTrapDensityC * Nl * Nl;
  T9 = (Nl + 2.0e14) * (Nl + 2.0e14);

  Ssi = T1 / T2 * (T3 + T4 + T5) + T6 / T7 * DelClm * T8 / T9;
  return Ssi;
}



int
BSIM3v32noise (int mode, int operation, GENmodel *inModel, CKTcircuit *ckt,
            Ndata *data, double *OnDens)
{
NOISEAN *job = (NOISEAN *) ckt->CKTcurJob;

BSIM3v32model *model = (BSIM3v32model *)inModel;
BSIM3v32instance *here;
struct bsim3v32SizeDependParam *pParam;
double tempOnoise;
double tempInoise;
double noizDens[BSIM3v32NSRCS];
double lnNdens[BSIM3v32NSRCS];

double vgs, vds, Slimit;
double T1, T10, T11;
double Ssi, Swi;

double m;

int i;

    /* define the names of the noise sources */
    static char *BSIM3v32nNames[BSIM3v32NSRCS] =
    {   /* Note that we have to keep the order */
        ".rd",              /* noise due to rd */
                            /* consistent with the index definitions */
        ".rs",              /* noise due to rs */
                            /* in BSIM3v32defs.h */
        ".id",              /* noise due to id */
        ".1overf",          /* flicker (1/f) noise */
        ""                  /* total transistor noise */
    };

    for (; model != NULL; model = model->BSIM3v32nextModel)
    {    for (here = model->BSIM3v32instances; here != NULL;
              here = here->BSIM3v32nextInstance)
         {    pParam = here->pParam;
              switch (operation)
              {  case N_OPEN:
                     /* see if we have to to produce a summary report */
                     /* if so, name all the noise generators */

                      if (job->NStpsSm != 0)
                      {   switch (mode)
                          {  case N_DENS:
                                  for (i = 0; i < BSIM3v32NSRCS; i++)
                                  {    NOISE_ADD_OUTVAR(ckt, data, "onoise.%s%s", here->BSIM3v32name, BSIM3v32nNames[i]);
                                  }
                                  break;
                             case INT_NOIZ:
                                  for (i = 0; i < BSIM3v32NSRCS; i++)
                                  {    NOISE_ADD_OUTVAR(ckt, data, "onoise_total.%s%s", here->BSIM3v32name, BSIM3v32nNames[i]);
                                       NOISE_ADD_OUTVAR(ckt, data, "inoise_total.%s%s", here->BSIM3v32name, BSIM3v32nNames[i]);
                                  }
                                  break;
                          }
                      }
                      break;
                 case N_CALC:
                      m = here->BSIM3v32m;
                      switch (mode)
                      {  case N_DENS:
                              NevalSrc(&noizDens[BSIM3v32RDNOIZ],
                                       &lnNdens[BSIM3v32RDNOIZ], ckt, THERMNOISE,
                                       here->BSIM3v32dNodePrime, here->BSIM3v32dNode,
                                       here->BSIM3v32drainConductance * m);

                              NevalSrc(&noizDens[BSIM3v32RSNOIZ],
                                       &lnNdens[BSIM3v32RSNOIZ], ckt, THERMNOISE,
                                       here->BSIM3v32sNodePrime, here->BSIM3v32sNode,
                                       here->BSIM3v32sourceConductance * m);

                              switch( model->BSIM3v32noiMod )
                              {  case 1:
                                 case 3:
                                      NevalSrc(&noizDens[BSIM3v32IDNOIZ],
                                               &lnNdens[BSIM3v32IDNOIZ], ckt,
                                               THERMNOISE, here->BSIM3v32dNodePrime,
                                               here->BSIM3v32sNodePrime,
                                               (2.0 / 3.0 * fabs(here->BSIM3v32gm
                                               + here->BSIM3v32gds
                                               + here->BSIM3v32gmbs)) * m);
                                      break;
                                 case 2:
                                 case 4:
                                            /* Added revision dependent code */
                                            if (model->BSIM3v32intVersion == BSIM3v32V324)
                                      {
                                        NevalSrc(&noizDens[BSIM3v32IDNOIZ],
                                               &lnNdens[BSIM3v32IDNOIZ], ckt,
                                               THERMNOISE, here->BSIM3v32dNodePrime,
                                               here->BSIM3v32sNodePrime,
                                               (m * here->BSIM3v32ueff
                                               * fabs(here->BSIM3v32qinv)
                                               / (pParam->BSIM3v32leff * pParam->BSIM3v32leff
                                                + here->BSIM3v32ueff * fabs(here->BSIM3v32qinv)
                                                * here->BSIM3v32rds)));    /* bugfix */
                                      }
                                            else
                                      {        /* for all versions lower then 3.2.4 */
                                        NevalSrc(&noizDens[BSIM3v32IDNOIZ],
                                               &lnNdens[BSIM3v32IDNOIZ], ckt,
                                               THERMNOISE, here->BSIM3v32dNodePrime,
                                               here->BSIM3v32sNodePrime,
                                               (m * here->BSIM3v32ueff
                                               * fabs(here->BSIM3v32qinv
                                               / (pParam->BSIM3v32leff
                                               * pParam->BSIM3v32leff))));
                                      }
                                      break;
                              }
                              NevalSrc(&noizDens[BSIM3v32FLNOIZ], NULL,
                                       ckt, N_GAIN, here->BSIM3v32dNodePrime,
                                       here->BSIM3v32sNodePrime, (double) 0.0);

                              switch( model->BSIM3v32noiMod )
                              {  case 1:
                                 case 4:
                                      noizDens[BSIM3v32FLNOIZ] *= m * model->BSIM3v32kf
                                            * exp(model->BSIM3v32af
                                            * log(MAX(fabs(here->BSIM3v32cd),
                                            N_MINLOG)))
                                            / (pow(data->freq, model->BSIM3v32ef)
                                            * pParam->BSIM3v32leff
                                            * pParam->BSIM3v32leff
                                            * model->BSIM3v32cox);
                                      break;
                                 case 2:
                                 case 3:
                                      vgs = *(ckt->CKTstates[0] + here->BSIM3v32vgs);
                                            vds = *(ckt->CKTstates[0] + here->BSIM3v32vds);
                                      if (vds < 0.0)
                                      {   vds = -vds;
                                          vgs = vgs + vds;
                                      }
                                            /* Added revision dependent code */
                                            if (model->BSIM3v32intVersion == BSIM3v32V324)
                                      {
                                        Ssi = StrongInversionNoiseEvalNew(vds, model,
                                                      here, data->freq, ckt->CKTtemp);
                                        T10 = model->BSIM3v32oxideTrapDensityA
                                            * 8.62e-5 * ckt->CKTtemp;
                                        T11 = pParam->BSIM3v32weff
                                            * pParam->BSIM3v32leff
                                            * pow(data->freq, model->BSIM3v32ef)
                                            * 4.0e36;
                                        Swi = T10 / T11 * here->BSIM3v32cd
                                            * here->BSIM3v32cd;
                                        T1 = Swi + Ssi;
                                        if (T1 > 0.0)
                                            noizDens[BSIM3v32FLNOIZ] *= m * (Ssi * Swi) / T1;
                                        else
                                            noizDens[BSIM3v32FLNOIZ] *= 0.0;
                                      }
                                            else
                                      {        /* for all versions lower then 3.2.4 */
                                        if (vgs >= here->BSIM3v32von + 0.1)
                                          {
                                            Ssi = StrongInversionNoiseEvalOld(vgs, vds, model,
                                                        here, data->freq, ckt->CKTtemp);
                                            noizDens[BSIM3v32FLNOIZ] *= m * Ssi;
                                          }
                                        else
                                          {
                                            pParam = here->pParam;
                                            T10 = model->BSIM3v32oxideTrapDensityA
                                                  * 8.62e-5 * ckt->CKTtemp;
                                            T11 = pParam->BSIM3v32weff
                                                  * pParam-> BSIM3v32leff
                                                  * pow (data->freq, model->BSIM3v32ef)
                                                  * 4.0e36;
                                            Swi = T10 / T11 * here->BSIM3v32cd * here->BSIM3v32cd;

                                            Slimit = StrongInversionNoiseEvalOld(
                                                 here->BSIM3v32von + 0.1, vds, model,
                                                 here, data->freq, ckt->CKTtemp);
                                            T1 = Swi + Slimit;
                                            if (T1 > 0.0)
                                                        noizDens[BSIM3v32FLNOIZ] *= m * (Slimit * Swi) / T1;
                                            else
                                                        noizDens[BSIM3v32FLNOIZ] *= 0.0;
                                          }
                                        }
                                        break;
                              }

                              lnNdens[BSIM3v32FLNOIZ] =
                                             log(MAX(noizDens[BSIM3v32FLNOIZ], N_MINLOG));

                              noizDens[BSIM3v32TOTNOIZ] = noizDens[BSIM3v32RDNOIZ]
                                                     + noizDens[BSIM3v32RSNOIZ]
                                                     + noizDens[BSIM3v32IDNOIZ]
                                                     + noizDens[BSIM3v32FLNOIZ];
                              lnNdens[BSIM3v32TOTNOIZ] =
                                     log(MAX(noizDens[BSIM3v32TOTNOIZ], N_MINLOG));

                              *OnDens += noizDens[BSIM3v32TOTNOIZ];

                              if (data->delFreq == 0.0)
                              {   /* if we haven't done any previous
                                     integration, we need to initialize our
                                     "history" variables.
                                    */

                                  for (i = 0; i < BSIM3v32NSRCS; i++)
                                  {    here->BSIM3v32nVar[LNLSTDENS][i] =
                                             lnNdens[i];
                                  }

                                  /* clear out our integration variables
                                     if it's the first pass
                                   */
                                  if (data->freq ==
                                      job->NstartFreq)
                                  {   for (i = 0; i < BSIM3v32NSRCS; i++)
                                      {    here->BSIM3v32nVar[OUTNOIZ][i] = 0.0;
                                           here->BSIM3v32nVar[INNOIZ][i] = 0.0;
                                      }
                                  }
                              }
                              else
                              {   /* data->delFreq != 0.0,
                                     we have to integrate.
                                   */
                                  for (i = 0; i < BSIM3v32NSRCS; i++)
                                  {    if (i != BSIM3v32TOTNOIZ)
                                       {   tempOnoise = Nintegrate(noizDens[i],
                                                lnNdens[i],
                                                here->BSIM3v32nVar[LNLSTDENS][i],
                                                data);
                                           tempInoise = Nintegrate(noizDens[i]
                                                * data->GainSqInv, lnNdens[i]
                                                + data->lnGainInv,
                                                here->BSIM3v32nVar[LNLSTDENS][i]
                                                + data->lnGainInv, data);
                                           here->BSIM3v32nVar[LNLSTDENS][i] =
                                                lnNdens[i];
                                           data->outNoiz += tempOnoise;
                                           data->inNoise += tempInoise;
                                           if (job->NStpsSm != 0)
                                           {   here->BSIM3v32nVar[OUTNOIZ][i]
                                                     += tempOnoise;
                                               here->BSIM3v32nVar[OUTNOIZ][BSIM3v32TOTNOIZ]
                                                     += tempOnoise;
                                               here->BSIM3v32nVar[INNOIZ][i]
                                                     += tempInoise;
                                               here->BSIM3v32nVar[INNOIZ][BSIM3v32TOTNOIZ]
                                                     += tempInoise;
                                           }
                                       }
                                  }
                              }
                              if (data->prtSummary)
                              {   for (i = 0; i < BSIM3v32NSRCS; i++)
                                  {    /* print a summary report */
                                       data->outpVector[data->outNumber++]
                                             = noizDens[i];
                                  }
                              }
                              break;
                         case INT_NOIZ:
                              /* already calculated, just output */
                              if (job->NStpsSm != 0)
                              {   for (i = 0; i < BSIM3v32NSRCS; i++)
                                  {    data->outpVector[data->outNumber++]
                                             = here->BSIM3v32nVar[OUTNOIZ][i];
                                       data->outpVector[data->outNumber++]
                                             = here->BSIM3v32nVar[INNOIZ][i];
                                  }
                              }
                              break;
                      }
                      break;
                 case N_CLOSE:
                      /* do nothing, the main calling routine will close */
                      return (OK);
                      break;   /* the plots */
              }       /* switch (operation) */
         }    /* for here */
    }    /* for model */

    return(OK);
}



