Hspice simulation problem

[srvn4041]

Can u please give me the setup of that version.

 

[basawaraj]

Am not sure what OS and version you are using.

The simplest would be to download the Windows version of HSPICE and WaveView and install them. Once installed, add a path to the license server.

 

[h_vogt]

HSPICE complains about undefined i in gx.
Remove the lines:
*proposed window function
*.func f(x,i,p)={1-(x-stp(-i))^(2*p)}
If you compare to
https://www.edaboard.com/threads/246769/#post1087576
you see an extra ; as an end of line comment delimmiter in addition to * in line
*;.func f(x,i,p)={1-(x-stp(-i))^(2*p)}

Holger

 

[Analogstudent]

Hello guys,

I'm doing the same code as it is described in https://www.edaboard.com/threads/246769/.
I have used the F-2011.09-SP1 version of HSPICE and the cut and paste of the code, but I can't get the hysteresis behavior and just get a linear result when plotting i(Vtest) against V(aa).
Also I have put runlvl=0 in the options.

What do you think is wrong with my simulation?

Thanks in advance

 

[keith1200rs]

Are you plotting the results of the transient analysis? You will not see the hysteresis in a single DC sweep.

Keith

 

[Analogstudent]

Yes I'm plotting the results from a transient analysis from my .tr0 file.

So, what you think?

 

[keith1200rs]

Show your code & results.

Keith

 

[Analogstudent]

My code is here:

* MEMRISTOR
* Ron, Roff - Resistance in ON / OFF States
* Rinit - Resistance at T=0
* D - Width of the thin film
* uv - Migration coefficient
* p - Parameter of the WINDOW-function
* for modeling nonlinear boundary conditions
* x - W/D Ratio, W is the actual width
* of the doped area (from 0 to D)
*

.SUBCKT memristor Plus Minus
+ Ron=100 Roff=16K Rinit=11K D=10N uv=10F p=10

* DIFFERENTIAL EQUATION MODELING *

.PARAM f(x,p)= '1-pow((2*x-1),(2*p))'
Gx 0 x value='I(Emem)*uv*Ron/pow(D,2)*f(V(x),p)'
Cx x 0 1 IC='(Roff-Rinit)/(Roff-Ron)'
Raux x 0 1T

* RESISTIVE PORT OF THE MEMRISTOR *
Emem plus aux value='-I(Emem)*V(x)*(Roff-Ron)'
Roff aux minus Roff

*Flux computation*

*Eflux flux 0 value={SDT(V(plus,minus))}

*Charge computation*

*Echarge charge 0 value={SDT(I(Emem))}

* WINDOW FUNCTIONS
* FOR NONLINEAR DRIFT MODELING *

*window function, according to Joglekar
*.func f(x,p)={1-(2*x-1)^(2*p)}
*proposed window function
*;.func f(x,i,p)={1-(x-stp(-i))^(2*p)}
.ENDS memristor

Xmemrist aa 0 memristor Ron=100 Roff=16K Rinit=11K D=10N uv=10F p=10
Vtest aa 0 SIN(0 1.2V 1 0 0 0)
.tran 1m 1s
.plot tran V(aa) I(Vtest)
.option list node post=2 ingold=2 runlvl=0
.end



and my results are like this:

 

[basawaraj]

Change the .tran statement to use initial conditions.

.tran 1m 1s UIC

This should take care of the issue you have.

 

[Analogstudent]

Thanks man, That was the problem.

Appreciate your help.

- - - Updated - - -

Basawaraj,

Please tell me if you have also used the second window function

*proposed window function
*;.func f(x,i,p)={1-(x-stp(-i))^(2*p)}

which has the stp function in it. I don't know what does this function mean, neither how can I introduce it in HSpice.

BTW, are you using HSpice to simulate your memristor circuits?
I was told that HSpice cannot handle the required non-linearity for memristor. I have heard that Eldo can do the job, but as I am more familiar with HSpice, I thought it might be worth trying HSpice first.

Cheers,
Analogstudnet

 

[basawaraj]

Hi,

'STP' is the step function / unit step function in PSPICE. In LTspice and Berkeley SPICE it is defined as 'U', that is replace STP(x) of PSPICE with U(x) in LTspice and Berkeley SPICE.

I do not think that HSPICE has a equivalent for the 'STP' function.

You might try using the signum function instead:

. PARAM f(x,i,p)='1-(x-(1-SGN(i))/2)**(2*p)'

I have not personally tried it, but in the Spectrum-Soft summer 2009 newsletter there is a memristor macro, using Micro-Cap, provided by Prof. Dalibor Biolek and it uses the signum instead of the step function.
https://www.spectrum-soft.com/news/summer2009/memristor.shtm

PS: Am not sure if the signum function in HSPICE behaves the same as that in Micro-Cap.