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steven852
Joined: 24 Apr 2005
Posts: 105
Helped: 1
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 16 Aug 2006 1:17 Re: Fixing setup/hold violations on SoC Encounter |
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| tags: eco setup hold |
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After running SoC Encounter with timing optimization, I still have a small amount of setup/hold violations to fix. They are around 20ps for hold and less than 6ps for setup. When I look at the timing reports, I think the hold time violations can be fixed by an ECO and the same as the setup violations. But I am not sure this is the right way to do that since the tool should be able to correct these violations. Any suggstions?
Thanks
Added after 56 minutes:
I forgot to say: setup and hold time analysis after pre CTS and post CTS are good. But setup/hold violations occur after post detail route.
Thanks.
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au_sun
Joined: 05 Aug 2004
Posts: 147
Helped: 10
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| 16 Aug 2006 7:48 Re: Fixing setup/hold violations on SoC Encounter |
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| tags: eco setup hold |
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The violations u have reported can be easily fixed by ECO,
Every time the tool may not give u the best timing,
and also looking into the timing violation values 20ps hold and 6ps setup, they can be fixed by using techniques like cell resizing, buffer insertion....
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dr.farnsworth
Joined: 05 Jan 2005
Posts: 56
Helped: 2
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| 16 Aug 2006 10:14 Re: Fixing setup/hold violations on SoC Encounter |
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Hello au_sun,
Can you in detail how cell resizing and buffer insertion is done ? do you have to repeat layout synthesize after cell resizing and buffer insertion?
Dr.farnsworth
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steven852
Joined: 24 Apr 2005
Posts: 105
Helped: 1
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| 17 Aug 2006 3:58 Re: Fixing setup/hold violations on SoC Encounter |
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| yeah, i fixed them with ECO. previously i made eco after add filler. for some unknown reasons, the eco didn't work.
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p_shinde
Joined: 25 Feb 2006
Posts: 295
Helped: 4
Location: tokyo
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| 17 Aug 2006 6:39 Re: Fixing setup/hold violations on SoC Encounter |
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in an eco, engineering change order, what parameters do one need to change?
hmm it would be nice if anyone can explain eco steps (flow)...
thanks,
Prasad
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steven852
Joined: 24 Apr 2005
Posts: 105
Helped: 1
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| 17 Aug 2006 21:50 Re: Fixing setup/hold violations on SoC Encounter |
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| tags: eco setup hold |
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After I digged deeper into the ECO procdure, I realized there are much more to judge. I hope someone can share their experiences in doing ECO:
1. which fixing goes first, setup or hold? The basic question is that when fixing one of the them, the other won't be affected significantly. This large change is what I am experiencing: I can fix either of them easily but the other gets worse
2. which point to fix, datapath or clock tree? What I tried was in the datapath.
3. Which choice is better, inserting buffers or changing cells?
Thanks.
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