Hi
I am a newbie. I want to plot S parameters in Cadence 6.1 . I have been trying hard but in vain. The problem is the port selection menu is not accepting any inputs from teh schematic. so it remains blank. and finally when i run the schematic then the LOG file shows that no ports detected..
What should i do?
Please Help
Hello,
Would someone please explain to me this issue when I use different versions of the spectre APS simulator? I was using the pnoise analysis on circuit that contains hicum (bht) model, by MMSIM 12.1 vs 7.2.
The MMSIM12.1 result is pessimistic and contains noise sources called iciei1 and iciei2 in the printed noise summary, while MMSIM7.2 result contains sources called it and fn in the printed noise summary.
I also come across errors during pss-tran with the slower Spectre simulator on the hicum (bht) circuit, but I don't have trouble running the same on the APS engine.
My IC version is 6.1.5.500.9 (both 32 and 64 bit have been tried).
Thank you.
Fred
using IC 5.10.40 in cadence ,,
i want to do corner analysis , i studied some manuals related to this ,, but i didn't understood how to add the process corners to my simulation ,, in this window " Add process " it is not showing any files ,, please help me to proceede ..
here i am attacthing the image also ,, pls hlep
Hello Sir,
I have been trying to design a UHF passive RFID tag in 130nm on Cadence Virtuoso IC 5.4.1. As for the design of a matching network between Antenna and Rectifier of RFID please tell me how reflections, if not matched, been modelled in Cadence Virtuoso. So whether I have to use any specifice ports or libraries for modelling the net to a transmission line for seeing the reflection due to mismatch.
Thanking you.
Regards,
Jithin
Sir,
First of all, let me thank u for helping me in my project work, by giving valuble information. We are using BSIM-CMG (DG-MOSFET) model for circuit analyses and earlier, we were getting the output waveforms as well as pss analysis results by using virtuoso 6.1.4 version. But last day, the version was upgraded to 6.1.5 and we are getting some errors which is shown as given below:
Error found by spectre during AHDL read-in.
ERROR (VACOMP-1008): Cannot compile ahdlcmi module library. Check the log file input.ahdlSimDB//1990_serverdemo_set2_bsimcmg_main_veriloga_veriloga.va.bsimcmg.ahdlcmi/Linux/../ahdlcmi.out for details. If the compiler ran out of memory, use 'setenv CDS_CMI_COMPLEVEL 0', and try again. If the reason for the failure was a syntax error, contact your Cadence Customer Support representative with the netlist, log files, behavioral model files, and any other information that can help identify the problem.
ERROR (SFE-91): Error when elaborating the instance bsimcmg. Simulation should be terminated.
We have tried a lot to get the input log file but failed. It would be grateful if you could provide me any solution to run this BSIM-CMG verilog-A model successfully. Thanks in advance.
Yours faithfully
Aravind
VIT University.
Hello,
I have an ADEXL state with two tests. I need to run different sweeps on the same variables.
Is there an option to sweep design variable (instead of global variable)?
How can I do that?
Thanks in advance,
Sarit
HI folks,
My question is:
in pnoise simulation, can I activate/deactivate specific voltage sources or instances as only noise contributor?
For example, in transient noise analysis, Virtuoso provdes a feature, 'Noise Contribution On/Off'' with a given instance list. I am looking for similar feature in pnoise analysis.
Virtuoso verion of mine is IC6.1.5-64b.500.12
I appreciate any comment from you.
Jae Wook
Hello.
I did see that there are three recent threads with very similar titles, but - unfortunately, with completely different problems described.
I use up-to-date MMSIM and IC5 (2012_2013 package installed on a 32 bit machine) and I have given a swap file to the PSS analysis. I am trying to get IIP3 post-layout simulation to run for my circuit (QRC used for extraction). I want it measured at 8 and 9 GHz with 200 MHz harmonics. I do only 6 steps for signals of power in the range of -20:5 dBm.
Nevertheless, the simulation breaks telling me - insufficient memory. During the simulation, it doesn't really use the file I gave it (<path>/Desktop/pss_swap - it's always 0 bytes). What it actually does is that it creates about twenty files called pss_swap_0, pss_swap_1, and so on, each of them about 1.2 GB. And it does this for every point of calculation.
Now, my question is, is it possible (and how?) to overcome this? If I choose a higher limit for extraction my S-parameters change, so I can not go higher on this. Less than 6 points... does it really make sense? Number of harmonics must remain the same since I need it calculated at certain frequencies.
Do you have any suggestions how to get this done?
Thank you very much for your time and effort.
Hello,
Could we use the transient analysis results as a stabilization point (tstab) for PSS analysis? If so, how could we acheive it? Is there any documentation on this? Any inputs will be helpful.
Prakash.
Hi,
I am simulating PSS+Pnoise on my LC oscillator for jc and jcc jitter measurement. From the phase noise plot I got positive value at low frequency offset, which I think makes the jitter calculation incorrect. I searched and read through some old threads with the same topic. It seems this issue is connected to the MMSIM version, but nobody clarified it. I am likely working with IC61+MMSIM60, although I need to check with the server manager. So is it the case that if I upgrade MMSIM, this issue "positive phase noise" can be solved? Or is there anything else I am missing? Thanks in advance.
Regards,
Hi.
I need to plot Cgs vs Vgs of a NMOS transistor. I have searched a lot and followed tutorial but still in vain. Below is my circuit for simulation. My schematic and setting is attached in the picture below. Here, I chose DC analyse, with Vgs sweeping from 0 to 2V.
I created a file, namely, oppoint.scs, and wrote its content as follows:
save M2:oppoint
Then I chose Netlist and Run.
However, the error below appeared.
(please see the attached file in the second post. I can't post two images in a single post).
I couldn't figure out why. I am completely new with Cadence and I can't use SKILL.
Hope you can help.
Thanks.
Hi.
I set up this circuit for simulation Cgs and Cgs as Vgs changes.
Below are the curves Cgs and Cgs vs Vgs.
(please see it in the second post. The forum doesn't allow to post two images in a single post)
I have some questions, hope you can help.
1. Why Cgs and Cgs are negative?
2. Why Cgs and Csg are not equal?
Thanks.
Hi.
I am plotting Gmin ( optimum noise reflection coefficient) of a LNA in Smith chart.
I swept Gmin versus frequency (for example, ranging from 1GHz to 3GHz).
Is there a way to read out optimum noise impedance at my interested frequency, say 2GHz, from the curve?
I know that I can point the cursor over the curve, find the interested frequency and then read out the impedance. However, that method is not exactly at all.
How to read exactly the value of impedance from the plotting of Gmin vs frequency?
Hi there,
We have a case where we have to use multiple model files in spectre simulation.
I want to avoid situation where by mistake different section names are used in the simulation.
E.g.
...
include "/home/predamar/tests/spectre/my_models/include.scs" section=fast
include "/home/predamar/tests/spectre/basic/include.scs"
include "/home/predamar/tests/spectre/my_models_2/include.scs" section=nom
...
In one place is used "fast", in other is "nom".
I want to have the possibility to provide an error message and to stop the simulation.
The include lines which have no "section" will be ignored.
So, all the included files should have the same section name.
The only solution that I see now is to trigger a script before starting spectre simulation,and to parse the top netlist file.
I want to know if spectre has something builtin that may help.
Best Regards,
Marcelsir i am ,, using IC 5.10.40 in cadence , ,,
I want to make monte carlo analysis for my circuit , but my seniors here are telling that monte carlo is not working here in the version ,, how can i check that ?..
i am just beginer ,
please reply ,,
I have upgraded to IC 615 from IC 613. But I am facing problems:
1. In spectre RF when I do s parameter simulation and try to plot gain circles (Ga,Gp etc) I get nothing. Noise circles work well. I can plot the gain curves wrt frequency though which shows data is available.
2. When I plot voltage conversion gain using pac then I get bar plot by default instead of solid line curve. Also in some plots I get in powers of ten form. How can I customize the plot?