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Minimum gap between wires in layout

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oAwad

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Hello,

How can I modify the minimum gap between wires of same metal in SoC encounter ?
 

I modify the LEF tech file and then restore the design again in SoC encounter but the minimum gap is still not modified.
Does SoC encounter take the spacing data only when place and route and then forgets about them, so if I change them SoC encounter won't realize ?
 

I modify the LEF tech file and then restore the design again in SoC encounter but the minimum gap is still not modified.
Does SoC encounter take the spacing data only when place and route and then forgets about them, so if I change them SoC encounter won't realize ?

Yes, obviously.
 

I'm sorry I think I misexplained what I'm trying to do...I'm not trying to modify the gap between all the wires in the layout, which obviously I have to run P&R to modify, but I'm trying to just manually modify the gap between two wires (using move wires option) in the layout beyond the minimum gap (which is 0.14u for example to be 0.7u) in order to measure effects of crosstalk between these two wires.
 

Are you trying to modify the routed metal? or the metal of Standard cell layout?.

If routed metal, then it should be possible manually (if you are looking at few cases)
whereas the Metal of Standard Cell layout can't be modified unless you regenerate the LEF/FRAM models after changing the layout/
 

Are you trying to modify the routed metal? or the metal of Standard cell layout?.

If routed metal, then it should be possible manually (if you are looking at few cases)
whereas the Metal of Standard Cell layout can't be modified unless you regenerate the LEF/FRAM models after changing the layout/

I'm trying to modify the gap between two routed metal wires of same metal. I modified two files "NangateOpenCellLibrary.lef" and "NangateOpenCellLibrary.tech.lef" for the minimum spacing between metal4 wires to be from 0.14u to 0.07u, but I still can't decrease the spacing between the two metal4 wires in the layout to this limit (using move wires).

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Another question, do you know if I can add a new net which is not in the netlist ? (I want to draw new wire and assign to it a net name which is not found in the netlist, is it possible?) If not can I edit the netlist to add this new net ...from SoC encounter ?

When I add a new wire manually using "Add wire", i should assign a net name before drawing so if I assign a new name I have an error "net name is invalid" and if I assign a name in the netlist (hopping to change it to a new name afterwords) I find that the net name of the wire is non-editable.
 

I'm trying to modify the gap between two routed metal wires of same metal. I modified two files "NangateOpenCellLibrary.lef" and "NangateOpenCellLibrary.tech.lef" for the minimum spacing between metal4 wires to be from 0.14u to 0.07u, but I still can't decrease the spacing between the two metal4 wires in the layout to this limit (using move wires).
.

Once you update the tech files, reload the design using restoreDesign command.
This should update the rules.

Unless you are having some DRC while routing the new route [reducing the space of metal], the change should be possible.

- - - Updated - - -

Another question, do you know if I can add a new net which is not in the netlist ? (I want to draw new wire and assign to it a net name which is not found in the netlist, is it possible?) If not can I edit the netlist to add this new net ...from SoC encounter ?

When I add a new wire manually using "Add wire", i should assign a net name before drawing so if I assign a new name I have an error "net name is invalid" and if I assign a name in the netlist (hopping to change it to a new name afterwords) I find that the net name of the wire is non-editable.

The new net to be assigned need to be in netlist for encounter I believe. Other-way as you did is not possible in Tool as per my understanding.
 

Once you update the tech files, reload the design using restoreDesign command.
This should update the rules.

Unless you are having some DRC while routing the new route [reducing the space of metal], the change should be possible.

The minimum spacing length is updated in SoC encounter to 0.07u as in the attached picture, but when I try to decrease the spacing from 0.14u to 0.07u, the wire don't want to move (due to DRC error) which I think is due to the accuracy of "move wire" using mouse (the wire doesn't want to move unless I move it at least a distance equal to its width)....so how to refine "move wire" ? and is there a command for that ? ( I tried searching the user guide but didn't find one).

new.PNG

Thanks for your help!
 

First of all, You need to confirm that the M4 spacing is 0.07u in Tech LEF.
Make sure to load the design again. restoreDesign (Assuming you are updating the Tech Lef directly - Initial File Only)

Now, coming to Encounter tool, move wire should move the metal based on the Manufacturing Grid mentioned in the Tech Lef.
This should the reference point.

I am not sure whether the EDI Tool behaves moving wire by pitch (ICC tool do behave this way,there we have control on this).

Can you retry using the resize button. Next to cursor button in your attached image ( 4 way direction :) ) . [Or In between Cursor button and Scale button]
 

First of all, You need to confirm that the M4 spacing is 0.07u in Tech LEF.
Make sure to load the design again. restoreDesign (Assuming you are updating the Tech Lef directly - Initial File Only)
Can you retry using the resize button. Next to cursor button in your attached image ( 4 way direction :) ) . [Or In between Cursor button and Scale button]

Thank you sir it worked, but I want to ask you if you can help me in understanding the output of SPEF file (see attached picture).
ask2.PNG

I know that the format of coupling cap. in SPEF should be "net:node net:node cap.value", but I don't understand what is meant by the node here and how to find it in the layout (I tried to search on it in the layout using the search tool but didn't find any search options for nodes)

ask3.PNG
Finally, I would like to know what does "relative C threshold" & "total C threshold" mean
ask1.PNG

Thanks a lot, I really appreciate your help
 

Not an expert here on this. I will get back if I find the answers.
 

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