VLSI chip design and development

hi guys,

what is the meaning of congestion w.r.t P&R.
Is congestion coming because of data flow or what i am not clear in the idea

In P& R , the scenario of the congestion could be felt, when there are lot of the logic sitting together in a close proximity.
Need to check on the congestion score upfront otherwise design would not be routable finally.

The reason could be for congestion is that the logic is not evenly distributed due to data flow, macro placement need to be revisited the pad ring need to be revisited.

Can think of regioning if possible may clear the congestion spots in the design.

Praise the Lord.

Hi

The congestion means there is no enough space for place or route of any cell or layer or net.

suppose you have only 10 routing track at perticular location and routing require 15 track it means there willll be a congestion ot this place.


Gaurav

hi,

congestion is due to densely placed cells and less amount of routing resources. when the routing channels are too narrow and there are more routes to be passed, it will result in routing congestion. the solution is to have nearly same channel spaces for both horizontal and vertical routing resources and examine the congested area for placement. If there are more routes to be passed is necessary then use of full or partial placement blockages will be good.

it may help u.

Thanks..

HAK..