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Faisal

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Layout Snap Spacing
May 07^th, 2007, 12:43am

In the Virtuso, Display options, through Layout Snap Spacing, I can control the X, Y snap spacing. What are the trade-offs or issues if I choose a too small snap spacing e.g. 0.001

The defualt X, Y snap spacing is at 0.5 but with this option I cannot place my PCELLS on the grid. I need the "RULER" for the layout rules etc and the RULER only works on the grid.

I am working on 0.18um. Has this something to do with the technology node?

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Faisal Community Member Offline Posts: 90	Re: Layout Snap Spacing Reply #1 - May 7^th, 2007, 1:29am I get the following warning message, when I set my snapSpacing to 0.001 in Virtuso Display Options WARNING 'ySnapSpacing' is not a multiple of 'mfgGridResolution' (0.005). Can anyone explain what is the significance of mfgGridResolution?
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didac Senior Member Offline There's a million ways to see the things in life Posts: 247 manresa,spain	Re: Layout Snap Spacing Reply #2 - May 7^th, 2007, 4:03am This parameter is a foundry limitation, is their ability to place the masks on the wafer, if you make a smaller grid probably when you check the DRC of the layout you will find lots of errors about 'offgrid', if you don't correct this errors the foundry will refuse your fabrication order.
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krishnap Community Member Offline Posts: 55	Re: Layout Snap Spacing Reply #3 - May 7^th, 2007, 9:04pm Usually process is done based on the MEBUS address unit. This is the minimum grid upon which process is possible. Any resolution below this manufacturing will not be possible. Also, Raster scanning method is used in fabrication based on this address unit.
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Faisal Community Member Offline Posts: 90	Re: Layout Snap Spacing Reply #4 - May 8^th, 2007, 2:56am Thanks, so it means the minimum snapSpacing i can choose is 0.005, as my mfgGridResolution (defined by technology file) is 0.005 ??
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didac Senior Member Offline There's a million ways to see the things in life Posts: 247 manresa,spain	Re: Layout Snap Spacing Reply #5 - May 8^th, 2007, 2:59am Yes, good luck with your layout.
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