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  3. Total Etch Length Matching

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Total Etch Length Matching

SLSCORP
SLSCORP over 3 years ago

How to set up constraint for this kind of etch length matching. Currently, it is very difficult process as we calculate it individually and sum it to match the total length. If a board is having multiple this kind of nets and more number of components in series then the length matching consumes too much time. What is the best method to do this kind of length matching?

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  • oldmouldy
    0 oldmouldy over 3 years ago

    This is what PCB Editor calls an XNet, eXtended Net. In any PCB Editor product, you can create XNets by assigning Signal Models to components with the Discrete Class property value through the Setup>More>SI Design Setup. (Setup>SI Design Setup with the legacy menus) Two pin components with the Discrete Class property value can be automatically assigned signal models based on Value. Components can also be moved between Classes during the setup to get them into the correct Class for SI. Once the setup is complete, the Constraint Manager will then list the "combined" Nets as XNets and Constraints can be applied to the entire XNet.

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  • oldmouldy
    0 oldmouldy over 3 years ago

    This is what PCB Editor calls an XNet, eXtended Net. In any PCB Editor product, you can create XNets by assigning Signal Models to components with the Discrete Class property value through the Setup>More>SI Design Setup. (Setup>SI Design Setup with the legacy menus) Two pin components with the Discrete Class property value can be automatically assigned signal models based on Value. Components can also be moved between Classes during the setup to get them into the correct Class for SI. Once the setup is complete, the Constraint Manager will then list the "combined" Nets as XNets and Constraints can be applied to the entire XNet.

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  • SLSCORP
    0 SLSCORP over 3 years ago in reply to oldmouldy

    Thanks for the reply...

    We tried to create xnets with the steps shown in below images but were unable to create. Created a simple schematic to test. Can you please help what steps we are missing?

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  • JuanCR
    0 JuanCR over 3 years ago in reply to SLSCORP

    Open your Constraint Manager (Setup > Constraints > Constraint Manager ...). Then go to Tools > Options and make sure that you have this option set up like this: 

    If you have it setup like this, you should see the Xnets automatically appear in your Electrical Worksheet.

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  • SLSCORP
    0 SLSCORP over 2 years ago in reply to JuanCR

    Thanks for your reply. We successfully created XNet with 2 pin discrete components. Is there any method to include IC's in the XNet?

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  • Schulz Jordan
    0 Schulz Jordan over 2 years ago in reply to SLSCORP

    The discretes can only be considered for XNets not ICs.

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  • steve
    0 steve over 2 years ago in reply to SLSCORP

    There is a solution on the Cadence Online Support site that may help:- How to create Xnets through ICs (cadence.com)

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