Placement (Part 1)

[@omaralmatov]

very helpful! thank you

[@JagatK_]

He mentions that the routing consumed 2 tracks or 3 tracks. What is meant by a track here ?

[@socialogic9777]

I think by track he means, the number of routing metal layers available.

[@JagatK_]

@@socialogic9777 No, that can’t be right. Because number of metal layers are usually quite high, at least > 15 or so.

[@socialogic9777]

@@JagatK_ th-cam.com/video/1Y-rQCs3ZNE/w-d-xo.html.
Go to 3:30

[@JagatK_]

@@socialogic9777 Yes, now it makes sense. So, the NDRs will consume more routing tracks or resources whereas normal nets will consume less tracks.
Thank you.

[@socialogic9777]

@@JagatK_ NDRs will cause congestion issues - a clock trunk can be NDR. However, overflow is caused with normal nets. In this case we will chose to perform net detours which can effect timing on critical nets.

[@socialogic9777]

Every concept like floorplanning, pin assignment and placement has been converted into a problem statement described with mathematical conjectures, probably to make it problem solvable by VLSI CAD tools. How do we do this?

[@JagatK_]

I think there are many algorithms used by those tools which helps them automate the placement and routing.

[@garrapallinareshkumar1997]

what difference between placement congestion and routing congestion

[@JagatK_]

Placement congestion happens when there is a congestion of modules (std cells, gates, etc).
Routing congestion happens when there is a congestion of the wires or the routes.