Hey All,
so when I disable the set ::env(FP_PDN_EN...
# ieee-sscs-dc-21q3o
Omiya Hassan
11/15/2021, 9:59 PMHey All,
so when I disable the set ::env(FP_PDN_ENABLE_RAILS) 0 it does a clean LVS, DRC check for my user_project_wrapper But if I enable the rail generation set ::env(FP_PDN_ENABLE_RAILS) 1, then I get illegal overlap errors.
Could anyone tell me why I'm getting this error
k
Krzysztof Herman
11/15/2021, 10:07 PMHi, I had issues with those errors as well. What worked for me was to place the macro in the default position "mprj 1175 1690 N" and then move it up and down by a factor of 180 (vertical pitch), the horizontal position seems not to cause a problems.
o
Omiya Hassan
11/15/2021, 11:51 PM@User you can also try something like that.
@User do i edit this in the macro.tcl file? Or in the config?
k
Krzysztof Herman
11/15/2021, 11:52 PMmacro.cfg
o
Omiya Hassan
11/15/2021, 11:53 PMThanks alot. Will update you
k
Krzysztof Herman
11/15/2021, 11:53 PM👍
o
Omiya Hassan
11/16/2021, 2:21 AMi tried a lot of combination of the position in factor of 180 but still getting similar overlap. Could you share your position that worked best for you?
g
Gokul Kuppuswamy
11/16/2021, 2:38 AM@User: Could you send you config.tcl file for user_project_wrapper?
Gokul Kuppuswamy
11/16/2021, 2:39 AMFor our design, we need to place three macros in the user_project_wrapper. In that case, what are the co-ordinates should we use?
k
Krzysztof Herman
11/16/2021, 2:50 AM@User my macro is at 70 250 N and is 2700x3100
Krzysztof Herman
11/16/2021, 2:51 AMg
Gokul Kuppuswamy
11/16/2021, 3:54 AM@User: You have also disabled Power Rail generation and you have also disabled "quit of LVS error". Could you tell why is that?
k
Krzysztof Herman
11/16/2021, 10:47 AM@User so the disabled Power Rail is the default value and seems to be ok since the wrapper module is supposed no to have any standard cells (the power rails are those horizontal rails where SC are connected). The wrapper do have power straps connected to the power rings. Make sure that only the horizontal straps are place over your macros and the vertical are blocked and there is some separation (obstruction) between macro and wrapper area. As for "quit on LVS error" I have disabled it just for testing to observe the flow after LVS errors, if there is no LVS error the flow continues as normal
g
Gokul Kuppuswamy
11/16/2021, 2:53 PM@User: In our case, I have some standard cells in the wrapper module. So, I must enable power rail generation right?
And how to make sure that only horizontal straps are placed over the macro and how to provide obstruction area for this?
k
Krzysztof Herman
11/16/2021, 3:32 PM@User I suppose having the extra logic in the wrapper is not a good idea, try to lower it to the user_project example. AFIK the obstruction is defined in the wrapper's LEF file, however would be nice someone could confirm it.