Problem with Power nets

Hi ,

I have an inquiry regarding the power nets in power planning step.
when I write get_nets VDD command after derive_pg_connection command, I get this warning message "Warning: No net objects matched 'VDD' (SEL-004)"
So, I can't understand what is the reason for this warning message?!
I attached below a copy of the command execution results.

Thanks in advance

icc_shell> derive_pg_connection -power_net VDD\
-ground_net VSS\
-power_pin VDD\
-ground_pin VSS
Information: connected 18799 power ports and 18799 ground ports
1
icc_shell> get_nets VDD
Warning: No net objects matched 'VDD' (SEL-004)

Are you sure that the power nets should be named
"VDD" and "VSS"? In the tools and PDKs I have used,
"vdd!" and "vss!" (global nets, for inherited connections)
or "vdd", "vss" (for direct-wired schematic design style)
are much more commonly used.

You might inspect one of the logic cells and see
what they think their power pins are called.

Try such command "get_nets -all VDD"

dick_freebird said:

Are you sure that the power nets should be named
"VDD" and "VSS"? In the tools and PDKs I have used,
"vdd!" and "vss!" (global nets, for inherited connections)
or "vdd", "vss" (for direct-wired schematic design style)
are much more commonly used.

Click to expand...

VDD and VSS are typical names in digital physical design. vdd!/vss! are more of a custom designer thing.

dick_freebird said:

Are you sure that the power nets should be named
"VDD" and "VSS"? In the tools and PDKs I have used,
"vdd!" and "vss!" (global nets, for inherited connections)
or "vdd", "vss" (for direct-wired schematic design style)
are much more commonly used.

You might inspect one of the logic cells and see
what they think their power pins are called.

Click to expand...

yes, I inspected them and their power pins are called VDD and VSS.

oratie said:

Try such command "get_nets -all VDD"

Click to expand...

icc_shell> get_nets -all VDD
{VDD}

This is the result of executing the command. So, does this mean that the Power nets are properly connected?

No, it only means, that you have power (or ground) net VDD in the design. Option -all include power/ground nets in get_nets result printing.

Information: connected 18799 power ports and 18799 ground ports - This means, that you have VDD/VSS connected to pins.

oratie said:

No, it only means, that you have power (or ground) net VDD in the design. Option -all include power/ground nets in get_nets result printing.

Information: connected 18799 power ports and 18799 ground ports - This means, that you have VDD/VSS connected to pins.

Click to expand...

Okay, thank you so much.