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Design Languages >> Verilog-AMS >> ddx operator implementation
https://designers-guide.org/forum/YaBB.pl?num=1232555156

Message started by ivan_petkov on Jan 21^st, 2009, 8:25am

Title: ddx operator implementation
Post by ivan_petkov on Jan 21^st, 2009, 8:25am

Hello everybody,
I am new in this forum and found it when trying to find a solution for my project.
So for my diplomacy work in Technical University in Bulgaria I have to implement a PSP MOS model in the working environment of the laboratory which is Cadence. I am really junior in this field so I hole you can help me a little.
The PSP model is supplied for free download form http://pspmodel.asu.edu and there is a VerilogA code proposed for SimKit simulator. In the laboratory we are using Cadence and VerilogA Version 5 2003 May. The original code seems to be written in newer version of VerilogA and therefor there were many syntax errors. The final situation is that compiler do not support "ddx" operator but only "ddt". So is there any way to implement this operator or somehow to bypass it with any equivalent functions so I can have the OP derivates calculated from the model?
Thanks a lot in advance! Have a nice day :)

Title: Re: ddx operator implementation
Post by Andrew Beckett on Jan 21^st, 2009, 3:56pm

You really should use a more recent version of spectre - you can use this in conjunction with an older environment, although a version from May 2003 is pretty old... newer versions should be available to most universities - are you part of Europractice?

Note that there was an issue with the ddx() usage in the PSP veriloga model which I worked on a few months ago - it was fixed in November 2008 in MMSIM (the stream containing spectre) 6.2.1.390 and also 07.01.162.isr14

Even with these builds, you have to do:

Code:

setenv CDS_AHDL_IGNORE_RESTRICT YES

because the code uses ddx() in a conditional statement (if the code is the same as the one I was looking at - it looks as if it is).

Regards,

Andrew.

Title: Re: ddx operator implementation
Post by ivan_petkov on Jan 22^nd, 2009, 12:25am

Thanks a lot Andrew,
probably I will leave the PO derivates for now, untill a new release is installed, and yes ddx() is in conditionals statement.
Yes I think we are working with Europractice and also MINOS-EURONET.
Thanks, Ivan