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ultrasim netlist stitching

KOTB

Hello,

 I am using ultrasim to simulate a spectre format netlist.

I want to stitch the capfile to the instance [XBLOCK.XRIBLET] using the following ultrasim option:

usim_opt capfile="[XBLOCK.XRIBLET]  /gsa/pokgsa-p12/13/magnetarkj/FlowRethink/ExtractedBlocks/MG_CR_RIBLET.cap"

My capfile contains only many capacitances extracted from the layout:

Cg18300 (XWLBLK\<0\>.DRV8\<62\>.WLD\<4\>.net042 GND) capacitor c=5.28362e-15
Cg18299 (XWLBLK\<0\>.DRV8\<62\>.WLD\<0\>.ND20.net8 GND) capacitor c=1.43045e-17
Cg18298 (XWLBLK\<0\>.DRV8\<62\>.WLD\<0\>.ND0.net8 GND) capacitor c=1.82924e-17
Cg18297 (XWLBLK\<0\>.DRV8\<62\>.WLD\<0\>.ND20.net8@2 GND) capacitor c=1.39314e-17
Cg18296 (XWLBLK\<0\>.DRV8\<62\>.WLD\<0\>.ND0.net8@2 GND) capacitor c=1.76248e-17
Cg18295 (XWLBLK\<0\>.DRV8\<62\>.WLD\<0\>.net041 GND) capacitor c=2.07346e-15
Cg18294 (XWLBLK\<0\>.DRV8\<62\>.WLD\<0\>.net087 GND) capacitor c=2.4252e-15
Cg18293 (XWLBLK\<0\>.DRV8\<62\>.WLD\<0\>.WRSELXX GND) capacitor c=6.01831e-15
Cg18292 (XWLBLK\<0\>.DRV8\<62\>.WLD\<0\>.net029 GND) capacitor c=2.10627e-15

When I run ultrasim, The stitching does not occur

I obtain the following error types in the spfrpt:

 18300 errors and 0 warnings(fixed errors) are issued (see file "stimulis.spfrpt")


***** File "/gsa/pokgsa-p12/13/magnetarkj/FlowRethink/ExtractedBlocks/MG_CR_RIBLET.cap" ****** :
ERROR (STITCH-0012)(:1) : Syntax error in Cg18300
ERROR (STITCH-0012)(:2) : Syntax error in Cg18299
ERROR (STITCH-0012)(:3) : Syntax error in Cg18298
ERROR (STITCH-0012)(:4) : Syntax error in Cg18297
ERROR (STITCH-0012)(:5) : Syntax error in Cg18296
ERROR (STITCH-0012)(:6) : Syntax error in Cg18295
ERROR (STITCH-0012)(:7) : Syntax error in Cg18294

....

The syntax of a capacitor in spectre format seems to me correct. Thus I do not understand the problem.

Please advise,

Regards,

Kotb

  • Andrew Beckett

    I had to look this up because capfile is an old format that even in UltraSim does not tend to be used any more (I can find hardly any references to it). It is not a spectre netlist that you're including - it would be (I believe)

    nodename1 value1
    nodename2 value2

    to be the grounded (decoupled) capacitance for each node.

    More commonly DSPF or SPEF stitching would be used instead with UltraSim.

    I would suggest that you contact customer support if you need more support (if the above does not answer your flow).

    Regards,

    Andrew.

  • KOTB
    in reply to Andrew Beckett

    Thank you Andrew,

    I will try with SPEF or DSPF. 

    I am referring to ultrasim userguide 2013-2014 where they mention that we can use SPEF/DSPF or CAPFILE. Maybe I should refer to the latest ultrasim userguie.

    Regards,

    Kotb

  • Andrew Beckett
    in reply to KOTB

    Hi Kotb,

    That's an old user guide, but it's the same in the current user guide. What it doesn't do is explain anywhere what the format of the "CAPFILE" is. It's not a spectre netlist though, which is what you were trying to use.

    Regards,

    Andrew.

  • KOTB
    in reply to Andrew Beckett

    Hi Andrew,

    I am using starRC to extract parasitics from the layout. 

    Could you please tell me if any extracted file by starRC will be accepted when using (usim_opt spef=" inst   inst.spf") ?

    Or, I have to set some options in starRC to give an extraxted netlist spf file which is compatible with ultrasim ?

    Thanks,

    Kotb

  • Andrew Beckett
    in reply to KOTB

    Hi Kotb,

    It should just be whatever is needed to produce a SPEF or DSPF file - I can't tell you what options in StarRC (a Synopsys tool) you'd need to set though. It's been a while since I've handled any Ultrasim stitching cases so probably best to follow this up through customer support if you need help with the flow.

    Regards,

    Andrew.

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