help about hsim VCS co-simulation problem

[hhq414]

Hi,all
I have a circuit which can be simulated by hsim, but when I use HSIM and VCS to do co-simulation.,there is a problen about the used lib:
ERROR:0x31501054:File "/spice/models/YI-115-SM003/hspice/sm115003.hspice", line 7752, column 100, format SPICE: Unsupported Charge-Conserved Capacitor
The above error is encountered when compiling(vcs -ad_hsim +ad=vcsAD.init verilog/**.v +vcs+dumpvars). Has anyone ever encountered this problem? How to solve it?

 

[ankitgarg0312]

hi,

few comments before coming to your problem:

from command u are using i am feeling that u are using older method of doing a cosimulation.
starting 2009.06 cosimulation methods has been changed significantly, please ensure that you are using latest manual/command for cosim.
u can ask solvnet for more details on this change and manual.

if possible to post vcsAD.init file in forum, ... i can have a quick look on same.

coming to your problem:

can you please elaborate what type of capacitor is there (line 7752 , as indicated by error).

i would suggest to create a small testcase with R,C circuit in analog domain ,and a pulse suppllied through verilog domain.
ensure that analog netlist is compiled individually by hsim, then proceed in cosim.
if cosim again gives error for unsupported model , please contact solvnet.
it can be a new device that need to be added in cosim methodology
( hsim alone and hsim-vcs cosim are not compelled to behave same, there is glue attaching both simulator and this new model may be not acceptable by that glue logic )

overall , create and small testcase with that device , and contact solvnet for better help on same.


hope this helps!!

 

[hhq414]

hi,

few comments before coming to your problem:

from command u are using i am feeling that u are using older method of doing a cosimulation.
starting 2009.06 cosimulation methods has been changed significantly, please ensure that you are using latest manual/command for cosim.
u can ask solvnet for more details on this change and manual.

if possible to post vcsAD.init file in forum, ... i can have a quick look on same.

coming to your problem:

can you please elaborate what type of capacitor is there (line 7752 , as indicated by error).

i would suggest to create a small testcase with R,C circuit in analog domain ,and a pulse suppllied through verilog domain.
ensure that analog netlist is compiled individually by hsim, then proceed in cosim.
if cosim again gives error for unsupported model , please contact solvnet.
it can be a new device that need to be added in cosim methodology
( hsim alone and hsim-vcs cosim are not compelled to behave same, there is glue attaching both simulator and this new model may be not acceptable by that glue logic )

overall , create and small testcase with that device , and contact solvnet for better help on same.


hope this helps!!

Thank you! I'll try as you suggested. The vcsAD.ini is as follow:
spice_top;
choose hsim spice/xxx.cdl;
use_verilog -module xxxx;
set bus_format [%d];
And the line 7752 is as follow:
Ca 5 20 q='Cmax*(v(5,20)/TR+(1-1/TR)/KCV*log((1+exp(KCV*(v(5,20)-Vmp-dVFB)))/(1+exp(KCV*(-Vmp-dVFB)))))'
Aslo the same error encountered in line 316:
Cs 1 2 q='c_ctot*c_temp*(v(1,2)+vc1*0.5*v(1,2)**2+vc2*1/3*v(1,2)**3)'

 

[ankitgarg0312]

Ur vcsad.init file looks ok..

this is a charge conseving capacitor...
i am not sure whether hsim-vcs will be able to handle it...

as i sugggested earlier make a small testcase of rc circuit and i suspect it will not work in cosimulation.
you can contact solvnet with that testcase so that they can help u with a enhancement request or so workaround .....

i have never used charge conserved capacitors earlier , can you elaborate where are such capacitors used?
are these for modelling some behavior or they are fabricated in silicon as well??

 

[hhq414]

Ur vcsad.init file looks ok..

this is a charge conseving capacitor...
i am not sure whether hsim-vcs will be able to handle it...

as i sugggested earlier make a small testcase of rc circuit and i suspect it will not work in cosimulation.
you can contact solvnet with that testcase so that they can help u with a enhancement request or so workaround .....

i have never used charge conserved capacitors earlier , can you elaborate where are such capacitors used?
are these for modelling some behavior or they are fabricated in silicon as well??

The charge conserved capacitors are used to model a nmos varactor,I don't know exactly why use it.