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From Virtuoso Layout to package & PCB

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Hello all,

I have a couple of newbie questions on the suggested design flow of the evaluation PCB for my chip design. I've done my chip design in Cadence Virtuoso, and sent it to the manufacturing house for tapeout and packaging. Now I would like to design a PCB for it in Cadence Allegro, and if possible simulate the whole IC-package-PCB system before manufacturing the PCB.

Packaging will be done for me, so far I can only get the physical characteristics of the package (type, dimensions, pin pitch etc), and I'm not sure that I will be able to obtain the details on how wire bonding was done. Therefore, I was thinking of exporting my IC data from Virtuoso, placing it inside a package I'd generate with Package Wizard, and doing simple autorouting.

1. For purposes of creating the package, how do I get my physical IC data into Allegro? Can I import it into the Package Designer, or do I need to go through Design Entry CIS, and which format to use?

2. For simulating the whole IC-package-PCB, can I use the netlist extracted by Mentor Graphics Calibre (includes all the parasitics)? What format should I extract the data into - HSPICE, Spectre or some other? What component of Allegro do I use for simulating (in Virtuoso I was using Analog Environment with Spectre or HSPICE models)?

Sorry for the long post - if there's some sort of a tutorial covering this flow, I'd appreciate info on where to find it. Thanks a lot in advance!

Pavle
University of Illinois


Originally posted in cdnusers.org by PavleM
Parents

  • Dan, thanks a lot for your reply. Perhaps I wasn't clear on package issues, I agree that it's extremely important. However, since I have no control over how it will be performed, and since my chip has low-speed inputs and outputs (~15 MHz), I feel modeling the package parasitics using several lumped elements with vendor-provided values should be sufficient (and the only possible option, given the lack of detailed packaging data).

    Back to my original issue, my IC is a mixed-signal low speed chip. I have the LQFP package footprint files I can use in PCB Editor. Now I need to relate this package to the Virtuso-designed IC inside it - what tool would you suggest for this purpose?

    I am currently attempting to create a new part in Design Entry CIS. I can set "PCB Footprint" property of the part to match the package footprint I have, but the only reasonable "Implementation Type" offered is "PSPICE Model". Now, I can extract my layout from Virtuoso using Mentor Graphics Calibre PEX (outputs HSPICE, Spectre, etc) or Assura RCX (outputs SPICE, Spectre, etc). Would Assura's SPICE output be the one to use as "Implementation" for the part?

    Or perhaps this method is completely off the mark - I would appreciate any suggestions.


    Originally posted in cdnusers.org by PavleM
Reply

  • Dan, thanks a lot for your reply. Perhaps I wasn't clear on package issues, I agree that it's extremely important. However, since I have no control over how it will be performed, and since my chip has low-speed inputs and outputs (~15 MHz), I feel modeling the package parasitics using several lumped elements with vendor-provided values should be sufficient (and the only possible option, given the lack of detailed packaging data).

    Back to my original issue, my IC is a mixed-signal low speed chip. I have the LQFP package footprint files I can use in PCB Editor. Now I need to relate this package to the Virtuso-designed IC inside it - what tool would you suggest for this purpose?

    I am currently attempting to create a new part in Design Entry CIS. I can set "PCB Footprint" property of the part to match the package footprint I have, but the only reasonable "Implementation Type" offered is "PSPICE Model". Now, I can extract my layout from Virtuoso using Mentor Graphics Calibre PEX (outputs HSPICE, Spectre, etc) or Assura RCX (outputs SPICE, Spectre, etc). Would Assura's SPICE output be the one to use as "Implementation" for the part?

    Or perhaps this method is completely off the mark - I would appreciate any suggestions.


    Originally posted in cdnusers.org by PavleM
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