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Design >> Analog Design >> Simulating SC filters with SpectreRF example
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Message started by delta sigma tim on Mar 28^th, 2004, 2:22pm

Title: Simulating SC filters with SpectreRF example
Post by delta sigma tim on Mar 28^th, 2004, 2:22pm

Hi,

I wonder if anyone who run the “Simulating SC filters with SpectreRF” example successfully can help me.

First I’m running spectre ver. 4.4.5.100.9 -- 20 Apr 2000. And I used the following command that is recommended by Cadence “Using AWD with standalone Spectre”: spectre +log spectre.out -f psfbin -r ./psf -E tah.ckt

I get the following warning:
“Warning from spectre during circuit read-in.
smpldNoise: `numberofpoints' is not a valid parameter for an instance of `pnoise'. Ignored.”

I also couldn’t figure out how to get `numberofpoints' option using the GUI either. Actually that is why I tried the standalone option.

Another problem I encountered with the example is with sh.va, I got the following error message:

“Error found by spectre during AHDL read-in.
"sh.va", line 29: "n = ($abstime <<--? - tdelay + aperture) / period + 0.5;"
"sh.va", line 29: Error: syntax error
"sh.va", line 34: "n = ($abstime <<--? - tdelay) / period + 0.0;"
"sh.va", line 34: Error: syntax error
"sh.va", line 39: "if (($abstime <<--? > tstop - aperture) && ($abstime <= tstop)) "
"sh.va", line 39: Error: syntax error
"sh.va", line 51: "if (($abstime <<--? >= tstop - aperture) && ($abstime < tstop))
begin"
"sh.va", line 51: Error: syntax error
file: sh.va. Non-recoverable error: parser error: confused context stack.
Exiting SpectreHDL compilation.”

thanks
Hi,

I

Title: Re: Simulating SC filters with SpectreRF example
Post by August West on Mar 28^th, 2004, 8:49pm

Tim,
Your version is too old. Time to upgrade. You can avoid the $abstime problem by using $realtime, but the other problem suggests that the version you are using does not support the strobed noise.

-August

Title: Re: Simulating SC filters with SpectreRF example
Post by Andrew Beckett on Mar 29^th, 2004, 5:55am

Actually it would support strobed noise, but you'd have to use noiseskipcount instead of numberofpoints - numberofpoints allows you to spread the strobe points over the PSS points by saying this is the total number of strobes you want; noiseskipcount says to do a strobe every nth timepoint.

tdnoise has been there (released) since IC445 - it was there in engineering mode before that. However, I'd recommend using a later version anyway... - you'll need that to get the newer verilog-a syntax, as August said.

Andrew.

Title: Re: Simulating SC filters with SpectreRF example
Post by delta sigma tim on Mar 29^th, 2004, 3:20pm

Thank you both very much. You are right, I had to update my source path to the newer version and everything works fine.

Thanks