LVS POWER AND GROUND NAMES

[henrywent]

lvs power

hi there,
I found two LVS command lines concerning power and ground name string variable setting which are as follows:
VARIABLE POWER_NAME ''AVDD'' ''DVDD'' '' AVD33'' ''AVD33''
VARIABLE GROUND_NAME ''AGND'' ''DGND'' ''DVD33'' ''AVD33''
my question is , do i have to use the power and ground name specified in the above two lines for the power and gnd in my layout,or can i specify my own power name such as ''myvdd'' in my layout. Can the LVS program recognize user-specified power and ground names? I really need your help, thanks in advance?
regards,
henry

 

[erikl]

lvspower

Hi Henry,
LVS instructions usually are PDK-specific, i.e. inherently foundry-specific. They use their own names for VDD, VSS, GND ... which relate to corresponding cell names in their libraries. If you want to tape-out a design to the foundry, you're bound to their libs and the corresponding pwr supply names. If you just want to play around with your own cells, you're free to use your own names, and in this case you can extend or change the names lists in the corresponding LVS instructions. But never for tape-out, because the foundry will always use their very own DRC and LVS files on the delivered designs.
erikl

 

[henrywent]

lvs power name

thank you very much,erikl
So I can use my own power and ground names in my layout cells before layout and do LVS, but when I am about to do tape out , I have to change my own power and ground names back to the foundry specific power and ground names, is that right? Correct me if I am wrong,thanks!

 

[ljw108]

lvs gnd

As I know, we are free to use any name for VDD and GND even in case of tape-out. LVS power name and LVS ground name are user-specific parts. Thus, users have to modify them to correspond with their design. But in some cases, people use the definite VDD and GND names for the sake of clarity.

 

[wpchan05]

lvs tapeout

Will foundries check lvs for their customers? I did submit a design to UMC thru IMEC, and they did drc only...

 

[Teddy]

foundry lvs

Foundry will not run LVS - you would have to provide your design database...

For the Calibre question above - you can pretty much delete those. Unless you will run PEX where you need to identify the gnd potential