metrics qualifying placement

[tachyons]

1) What are the pre requisites to start placement stage? What are the different techniques to relieve conjestion ? what metrics you look at to qualify placement before proceeding to next stage?
2) How are clock gaters and spare cells handled in placement stage?

 

[phoenixpavan]

Hi tachyons,

we need to have
1. Synthesized RTL netlist
2. SDC
3. Data setup and Design planning completed.
4. Hard macros placed and fixed

After floorplanning we check for issues such as
1.Cells placed in “hard placement blockage” areas
2. Metal layer inconsistencies against the library
3. R/Cs for routing layers
4. Narrow placement regions (“chimneys”)
5. Legal sites for cell placement
6. Large RC variations between metal layers

we also perform ZIC analysis that our SDC is not overconstraiing(unrealistic) the design

cheers