Handling BlackBox through Synthesis and PnR

[kalar]

Hi guys!

I am new here and i would like to ask how can I create blackboxes (or Hard macrocells??) in Synthesis and PnR stages. I am only asking for general guidelines as i don't want to make things much complicated for you.

So for example I have an RTL code and i want to synthesize (Design compiler) the top design but also to keep some submodules as blackboxes because i don't need them in timing analysis and also i would like to speed up the process of synthesizing. Then after I do this i want to export the netlist and import it to Encounter. At PnR stage i would like to see the black boxes so to make a better floorplan.

Any ideas?

Thank you guys.

 

[rca]

you could create a lib/lef for these submodule, and during the synthesis & pnr it will used it instead the code.

 

[kalar]

Ok cool, Thanx.

Just a follow up question, do you know any good tutorial of how to create lib/lef files for submodules?

 

[rca]

if you don't care of the timing you just need a text editor.
Same for the LEF.
i usually used scripts to generate the LEF with the expected waveform, and place pins in one border.
For the liberty I used script in PT with quicklib model