Floorplan estimation

[kumaranurag21]

Hi everyone

Lets say I have a netlist consisting of 200k gates and I have to estimate die area and floorplan and deliver the DEF to placement team. How do I go about it ?

 

[OhaAmo]

It is library and process dependent. Each cell has got its area according to a specific library. Go through all your cells and multiply each cell in its corresponding area from your vendor's library. Then you can take some density factor - usually for a standard design you should have around 80% density after placement. So from this data you can estimate your required die area.

 

[kumaranurag21]

Thanx for the reply

One more thing, regarding floorplan....what is the funda of using nand equivalent for estimation of size of the cell for estimating the shape and size of my floorplan ??

 

[kumar_eee]

One more way of doing it is, Load the design in the implementation tool, try to change the floorplan ( x & y coordinates ) in a such a way that the Starting utilization will be around 50% -to- 60%.

Again, it depends on the netlist quality & netlist completion status ( like Netlist is 75%, 80% & 90% completed ).