Cadece Monte-Carlo simulation

[EHY]

I want to know how to do monte-carlo simulation in cadence 5.14/6.15 version.

could you give me some tutorials about monte-carlo simulation in cadence??


help me

 

[erikl]

S. the attached file in this post!

 

[Dominik Przyborowski]

One remark to above. In 6th version of virtuoso You doing MC in ADE (G)XL environment

 

[EHY]

i have question.

for example,

if i want to do monte-carlo simulation by varying only one specific variable (ex. oxide thickness of mosfet ), how can i do??

i understand that if i attach monte-carlo library, then monte-carlo simulation will be done about many variable (ex. device mismatch(Width, Length, Vth...) or Process varaition, or Mismatch/Process )

 

[erikl]

Just (out)comment the vary lines which you don't want to be varied in the STATISTICAL Section of the model file (s. slide 11 of the above linked tutorial).

 

[EHY]

so, you mean i have to manipulate (fix) monte-carlo library in PDK???

Just (out)comment the vary lines which you don't want to be varied in the STATISTICAL Section of the model file (s. slide 11 of the above linked tutorial).

 

[erikl]

you mean i have to manipulate (fix) monte-carlo library in PDK???

No. Copy it to a new file, out-comment there what you don't want, and .include this file instead of the original one.

 

[EHY]

is it possible to do monte-carlo simulation with swept variable??? (cadence 5.14 version)

ex.) delay(variable) is swept from 0 to 0.7ns with simultaneously monte-carlo simulation

 

[erikl]

is it possible to do monte-carlo simulation with swept variable??? (cadence 5.14 version)

Yes, you can do that, s. p. 24 of the above linked-to tutorial. In this menu you can select the parameter to be swept. Here's an example for the result of such an MC sweep (feedback element value of opAmp swept):

 

[EHY]

Sorry but, Swept Parameter can be set only scalar value right??

i want to make the parameter 'delay' swept like in ADE window, Prametic Analysis

how can i do that??

 

[erikl]

Same as with any other parameter: give it a name, and write this 'name' where it should take place for your delay (e.g. in a vsource).

 

[EHY]

Same as with any other parameter: give it a name, and write this 'name' where it should take place for your delay (e.g. in a vsource).

I don't understand,,

' delay' is parameter what i want to sweep from 0ns to 0.7ns

but, Swept Prarmeter menu can be set only one value.

So how can i set from 0 to 0.7ns??

you mean that i have to set a value just one by one???

but, i want to PD monte-carlo simulated PD gain curve (when delay is swept 0 to 0.7ns)

 

[erikl]

If you want to sweep a 'delay', you have to put this parameter where it should cause this delay: e.g. in a vsource

Vxxx n+ n- PU[LSE] [(]v1 v2 [[B]td[/B] [tr [tf [pw [per]]]]] [)] + [PERJITTER=val [SEED=val]]

or in a Edelay element:

Edelay in_delay 0 DELAY in 0 TD='td1'	$$ signal "in_delay" is the "in" signal delayed by TD='[B]td1[/B]' 
+ where [B]td1[/B] is your parameter to be swept.

... or in any other element/model/subcircuit where you need this parameter.

BTW: It is possible that DELAY is a reserved keyword in SPICE, so you shouldn't name your parameter so, but (e.g.) td, td1, td2 .