memristor code model in extradev

14 years ago · f53eb5cf78
4 changed files with 272 additions and 0 deletions
--- a/examples/memristor/memristor_x.sp
+++ b/examples/memristor/memristor_x.sp
@ -0,0 +1,76 @@
+Memristor with threshold as XSPICE code model
+* Y. V. Pershin, M. Di Ventra: "SPICE model of memristive devices with threshold", 
+* arXiv:1204.2600v1 [physics.comp-ph] 12 Apr 2012, 
+* http://arxiv.org/pdf/1204.2600.pdf
+
+* XSPICE code model, parameter selection and plotting by
+* Holger Vogt 2012
+
+.param stime=10n
+.param vmax = 3
+
+* send parameters to the .control section
+.csparam stime={stime}
+.csparam vmax={vmax}
+
+*Xmem 1 0 memristor
+* triangular sweep (you have to adapt the parameters to 'alter' command in the .control section)
+*V1 1 0 DC 0 PWL(0 0 '0.25*stime' 'vmax' '0.5*stime' 0 '0.75*stime' '-vmax' 'stime' 0)
+* sinusoidal sweep
+V1 0 1 DC 0 sin(0 'vmax' '1/stime')
+
+
+* memristor model with limits and threshold
+* "artificial" parameters alpha, beta, and vt. beta and vt adapted to basic programming frequency 
+* just to obtain nice results!
+* You have to care for the physics and set real values! 
+amen 1 2 memr
+.model memr memristor (rmin=1k rmax=10k rinit=7k alpha=0 beta='20e3/stime' vt=1.6)
+
+vgnd 2 0 dc 0
+
+* This is the original subcircuit model
+.subckt memristor plus minus PARAMS: Ron=1K Roff=10K Rinit=7.0K alpha=0 beta=20e3/stime Vt=1.6 
+Bx 0 x I='((f1(V(plus)-V(minus))> 0) && (V(x) < Roff)) ? {f1(V(plus)-V(minus))}: ((((f1(V(plus)-V(minus)) < 0) && (V(x)>Ron)) ? {f1(V(plus)-V(minus))}: 0)) '
+Vx x x1 dc 0
+Cx x1 0 1 IC={Rinit} 
+Rmem plus minus r={V(x)} 
+.func f1(y)={beta*y+0.5*(alpha-beta)*(abs(y+Vt)-abs(y-Vt))} 
+.ends
+
+* transient simulation same programming voltage but rising frequencies
+.control
+*** first simulation ***
+* approx. 100 simulation points
+let deltime = stime/100
+tran $&deltime $&stime uic
+* plot i(v1) vs v(1)
+*** you may just stop here ***
+* raise the frequency
+let newfreq = 1.1/stime
+let newstime = stime/1.1
+let deltime = newstime/100
+alter @V1[sin] [ 0 $&vmax $&newfreq ]
+tran $&deltime $&newstime uic
+* raise the frequency even more
+let newfreq = 1.4/stime
+let newstime = stime/1.4
+let deltime = newstime/100
+alter @V1[sin] [ 0 $&vmax $&newfreq ]
+tran $&deltime $&newstime uic
+* the resistor currents
+plot tran1.alli tran2.alli alli title 'Memristor with threshold: currents'
+* calculate resistance (avoid dividing by zero)
+let res = v(1)/(I(v1) + 1e-16)
+let res1 = tran1.v(1)/(tran1.I(v1) + 1e-16)
+let res2 = tran2.v(1)/(tran2.I(v1) + 1e-16)
+* resistance versus time plot
+settype impedance res res1 res2
+plot res vs time res1 vs tran1.time res2 vs tran2.time  title 'Memristor with threshold: resistance'
+* resistance versus voltage (change occurs only above threshold!)
+plot res vs v(1) res1 vs tran1.v(1) res2 vs tran2.v(1) title 'Memristor with threshold: resistance'
+* current through resistor for all plots versus voltage
+plot i(v1) vs v(1) tran1.i(v1) vs tran1.v(1) tran2.i(v1) vs tran2.v(1) title 'Memristor with threshold: external current loops'
+.endc
+
+.end
--- a/src/xspice/icm/xtradev/memristor/cfunc.mod
+++ b/src/xspice/icm/xtradev/memristor/cfunc.mod
@ -0,0 +1,109 @@
+/* ===========================================================================
+FILE    cfunc.mod
+
+MEMBER OF process XSPICE
+
+Copyright 2012
+Holger Vogt
+Mülheim, Germany
+All Rights Reserved
+
+
+
+AUTHORS
+
+    6/08/2012  Holger Vogt
+
+MODIFICATIONS
+
+    <date> <person name> <nature of modifications>
+
+SUMMARY
+
+    This file contains the definition of a memristor code model
+    with threshold according to
+	Y. V. Pershin, M. Di Ventra: "SPICE model of memristive devices with threshold", 
+    arXiv:1204.2600v1 [physics.comp-ph] 12 Apr 2012, 
+    http://arxiv.org/pdf/1204.2600.pdf.
+	
+	** Experimental, still to be tested in circuits !! **
+
+INTERFACES
+
+    cm_memristor()
+
+REFERENCED FILES
+
+    None.
+
+NON-STANDARD FEATURES
+
+    None.
+
+=========================================================================== */
+
+/*=== INCLUDE FILES ====================*/
+
+#include <math.h>
+
+
+#define RV  0
+
+/* model parameters */
+double alpha, beta, vt;
+/* forward of window function */
+double f1(double y); 
+
+void cm_memristor (ARGS)
+{
+//    Complex_t   ac_gain;
+    double      partial;
+    double      int_value;
+    double      *rval;
+	double      inpdiff;
+	
+    /* get the parameters */
+	alpha = PARAM(alpha);
+    beta = PARAM(beta);
+    vt = PARAM(vt);	
+
+    /* Initialize/access instance specific storage for resistance value */
+    if(INIT) {
+        cm_analog_alloc(RV, sizeof(double));
+        rval = (double *) cm_analog_get_ptr(RV, 0);
+        *rval = PARAM(rinit);
+    }
+    else {
+        rval = (double *) cm_analog_get_ptr(RV, 0);
+    }
+
+    /* Compute the output */
+    if(ANALYSIS == TRANSIENT) {
+	    /* input the voltage across the terminals */
+	    inpdiff = f1(INPUT(memris));
+	    if ((inpdiff > 0) && (*rval < PARAM(rmax)))
+		    int_value = inpdiff;
+		else if  ((inpdiff < 0) && (*rval > PARAM(rmin)))
+		    int_value = inpdiff;
+        else
+		    int_value = 0.0;
+		/* integrate the new resistance */	
+        cm_analog_integrate(int_value, rval, &partial);
+		/* output the current */
+        OUTPUT(memris) = INPUT(memris) / *rval;
+        PARTIAL(memris, memris) = partial;
+    }
+/* no AC and DC modeling so far !	
+    else if(ANALYSIS == AC) {
+        ac_gain.real = *vc;
+        ac_gain.imag = 0.0;
+        AC_GAIN(memris, memris) = ac_gain;
+    }	*/
+}
+
+/* the window function */
+double f1(double y) {
+    return (beta*y+0.5*(alpha-beta)*(fabs(y+vt)-fabs(y-vt)));
+}	
+
+
--- a/src/xspice/icm/xtradev/memristor/ifspec.ifs
+++ b/src/xspice/icm/xtradev/memristor/ifspec.ifs
@ -0,0 +1,86 @@
+/* ===========================================================================
+FILE    ifspec.ifs
+
+MEMBER OF process XSPICE
+
+Copyright 2012
+Holger Vogt
+Mülheim, Germany
+All Rights Reserved
+
+
+
+AUTHORS
+
+    06/08/2012  Holger Vogt
+
+MODIFICATIONS
+
+    <date> <person name> <nature of modifications>
+
+SUMMARY
+
+    This file contains the definition of a memristor code model
+    with threshold according to
+	Y. V. Pershin, M. Di Ventra: "SPICE model of memristive devices with threshold", 
+    arXiv:1204.2600v1 [physics.comp-ph] 12 Apr 2012, 
+    http://arxiv.org/pdf/1204.2600.pdf.
+	
+	** Experimental, still to be tested in circuits !! **
+
+INTERFACES
+
+    None.
+
+REFERENCED FILES
+
+    None.
+
+NON-STANDARD FEATURES
+
+    None.
+
+=========================================================================== */
+
+NAME_TABLE:
+
+Spice_Model_Name:      memristor
+C_Function_Name:       cm_memristor
+Description:           "Memristor interface"
+
+
+PORT_TABLE:
+
+Port_Name:             memris
+Description:           "memristor terminals"
+Direction:             inout
+Default_Type:          gd
+Allowed_Types:         [gd]
+Vector:                 no
+Vector_Bounds:          -
+Null_Allowed:          no
+
+
+PARAMETER_TABLE:
+
+Parameter_Name:        rmin                      rmax                   rinit
+Description:           "minimum resistance"      "maximum resistance"   "initial resistance"
+Data_Type:             real                      real                   real
+Default_Value:         10.0                      10000.0                7000.0
+Limits:                -                         -                      -
+Vector:                 no                       no                     no
+Vector_Bounds:          -                        -                      -
+Null_Allowed:          no                        no                     no
+
+PARAMETER_TABLE:
+
+Parameter_Name:        alpha                     beta                    vt
+Description:           "model parameter 1"       "model parameter 2"    "threshold"
+Data_Type:             real                      real                   real
+Default_Value:         0.0                       1.0                    0.0
+Limits:                -                         -                      -
+Vector:                no                        no                     no
+Vector_Bounds:         -                         -                      -
+Null_Allowed:          no                        no                     no
+
+
--- a/src/xspice/icm/xtradev/modpath.lst
+++ b/src/xspice/icm/xtradev/modpath.lst
@ -7,3 +7,4 @@ lcouple
 lmeter
 potentiometer
 zener
+memristor