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    wire delay versus cell delay, how to evaluate?

    As we all know, the wire delay would contribute more to path delay as technologies shrink down, such as 45nm node. But how to evaluate it before real design? I know we could layout small circuit to see the delay percentage, if we want to compare the wire delay in two technologies, such as 90nm and 45nm, what can we do to reflect the real case, like, the circuit topology(what circuit)? drive strength, wire level (how many metal layers we use in this example) and the wire length.........
    Do anyone have suggestions? OR any prior work that I can reference to?


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    Re: wire delay versus cell delay, how to evaluate?

    There are basically n number of solutions, its upto you to decide which one you want to follow.

    Going from 90nm to 45nm, You have to make sure before running simulations that you actually calculate the delay difference ONLY due to wires and not because of other technological factors. Prepare a setup for the same.

    If you dont feel like doing this by yourself, let me know. I will provide the complete solution but you will learn only when you think and try to do by yourself.

    Cheers!!!



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  3. #3
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    Re: wire delay versus cell delay, how to evaluate?

    Now the Physical Compiler can solve this problem!



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  4. #4
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    wire delay versus cell delay, how to evaluate?

    To onlymusic16:
    Yes, the tricky part is how to take out the unnecessary factor. In my mind, I have to resort to ring oscillator wi/wo interconnect with minimum rule. But I don't know if this will reflect the real case.
    "n solutions" scared me~~, i'm good at device but not so good at circuit, :)
    If you have good suggestions, pls share with me, many thanks!!

    Added after 3 minutes:

    Hi, ljxpjpjljx
    Any further infomation about Physical Compiler to evaluate the wire delay? Do you mean setup a test circuit using PC and check the delay percentage?

    thanks,



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