SVT to HVT cell conversion

[a_shirwaikar]

Hi

I need an efficient way to convert all the SVT cells in an existing design to HVT cells.
I already know about a command 'ecoChangeCell' which performs this function. I have used it in a simple loop which checks each instance in the design, determines if it corresponds to an SVT cell and if yes, then changes it to an HVT cell. However, it will require a lot of time to convert every single cell (there are over 2 million if I'm correct).
Can anyone suggest another technique??

Oh and I need to use Cadence SoC Encounter

 

[lostinxlation]

dump out .def file and run perl script to replace all the SVT cells and read it back to FE ?

 

[kumar_eee]

Get all the cells used in the design & create a map table. use this map table to change your cells.

Map table could be like this.
and2_svt_1 and2_hvt_1
or2_svt_1 or2_hvt_1

create an array like below
set cells(and2_svt_1) "and2_hvt_1"
set cells(or2_svt_1) "or2_hvt_1"

Get the instance cell name & if its equal to 'and2_svt_1' then replace it with 'and2_hvt_1'

I guess there could be some other way as well.

 

[somg]

I'm not a big fan of this method. But here is an option.
Dump out a verilog. Change all hvt_ to svt_ and read the netlist back into to ICC/whichever. That tool should be able to generate the ECO script for you.

 

[jiancongwoo]

one question here.
if u swap all svt cell to hvt cell, do u think about timing ??

 

[a_shirwaikar]

modifying the def file isnt an option either because the netlist always has priority over the def.. so encounter will ignore cell conversions when it loads the netlist..

nope, timing is not a factor. This is for complete leakage power analysis. All HVT's should theoretically give me minimum leakage.. I need to determine how much the estimated value varies from the post Si one..

ecoChangeCell did work.. It just needed to be tweaked a bit.. Anyway, thanks guys

---------- Post added at 16:11 ---------- Previous post was at 16:10 ----------

Oh, and could anyone direct me to some excellent documents on power estimation techniques and low power techniques??
Thanks!

 

[kumar_eee]

Hi a_shirwaikar, Can you please post the exact procedure on what you've done?

 

[lostinxlation]

modifying the def file isnt an option either because the netlist always has priority over the def.. so encounter will ignore cell conversions when it loads the netlist..

Then do modify the netlist. You can just use a global substitution on vi with some regexp.

 

[kumar_eee]

I think using 'Vi' editor will be the efficient way as you don't need any license. But make sure that you've loaded all the Vt libraries before you replace the cells.