[SOLVED] Rectilinear Cut in Cadence Encounter

[chuggington]

I am working on a chip that needs to be shaped like an inverted "E". I was trying out the option as per what is mentioned in the user guide, but it doesnt seem to work. How do you work on Rectilinear designs ? What do you do to attain the shape u want ? I was trying the gui option , as I am not that proficient in scripting.

 

[trav1s]

During floor-planning, the following command will create an "E" shaped routing blockage on all layers:

createRouteBlk -layer all -polygon 0 0 0 500 400 500 400 400 100 400 100 300 400 300 400 200 100 200 100 100 400 100 400 0

Then when you place and route your design it will be in the shape of an inverted "E" as desired. See the SoC Encounter command reference for details about createRouteBlk. Or type "help createRouteBlk" in the CLI for just the syntax. Adjust the coordinates as needed.

 

[chuggington]

Thanks trav1s, but is this to create a blockage ? That could be an option too , but i was wondering if there is any way to have the basic floorplan itself in the shape of an E ? basically i would need to cut off two portions off the normal rectangular floorplan to get this. Any suggestions ?

 

[rca]

Hi chuggington,

I don't exactly understod your issue, you could cut the unwanted rows, that'is?
Are you able to share a picture of the expected flooplan?

 

[chuggington]

Hello - I just wanted to know if it is possible to have an E shaped or L shaped floorplan ? Unfortunately, no pic with me.

 

[rca]

yes you could.

---------- Post added at 10:52 ---------- Previous post was at 10:51 ----------

my floorplans are rarely floorplan due to analog module connected to the digital.

 

[chuggington]

Do you know how it could be done ?

 

[yadavvlsi]

You can create a rectilinear floorplan for a block in Encounter either using the GUI or using the text command setObjFPlanPolygon.

Using the GUI:
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1. Select the "Floorplan View" widget in the upper right.
2. Select the "Cut Rectilinear" widget (5th widget from the left directly above the art work window).
3. You will now cut away a section of the floorplan by drawing a box from the edge. Move the cursor over the edge of the block where you want to start the cut. The cursor will change into a double arrow "<-->". Left-click and then move the cursor to draw the area you want to cut out. Left-click again. The area is now removed.
4. Repeat step 3 to cut out additional areas.

Using setObjFPlanPolygon:
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Using the setObjFPlanPolygon command allows you to specify the exact coordinates of the floorplan. Specify the name of the design followed by the coordinates of the polygon. For example:

setObjFPlanPolygon <objectType> <objectName> x1 y1 x2 y2 x3 y3 x4 y4 x5 y5 x6 y6 ...

where <objectType> can be {cell | group | instance | layershape | module | net | pin}

Type "help setObjFPlanPolygon" at the encounter prompt to get the complete syntax.

Note: These commands only work on blocks and will not work at the chip level where the design contains cells which are defined in the LEF as CLASS PAD. For creating the rectiliner shape at the chip level refer the below link which tell about the new option "EnableRectilinearDesign".

 

[chuggington]

Exactly what i wanted to know. Thank you very much. Could you post the link again ? It was not there in your post above.

Edited to add : The culprit was the *PAD* names - I took them off the design and it works ! Do you know why it is like that ?

 

[yadavvlsi]

Rectilinear shape is not allowed on top level hierarchical design. Rectilinear shape is only allowed at the block level. Because it is hard to tell whether the current design is block level or not, IO cells are used to decide. In release EDI 10.1 USR1, a new Preference "EnableRectilinearDesign" was added on the Preferences -> Design page. Once you turn on it, it will let you set the rectilinear shape (or GUI cut) anyway.

 

[chuggington]

Thank you very much !