What are supply nets and supply ports in UPF?
From PDVerse Low-Power Physical Design Mentor Guide · pdVerse Mentor Guide
Definition
A supply net in UPF is a conductor that carries a supply voltage or ground reference to a power domain (created with create_supply_net), while a supply port is the UPF-level connection point (created with create_supply_port) used to bring a supply net into or out of a hierarchical scope; connect_supply_net then wires a net to a list of ports.
Mentor Explanation
A beginner often confuses these with actual physical wires, but at the UPF stage they are abstract intent objects — nets and ports describe how supplies are meant to be structured before physical implementation ties them to real rails. The important point is that a supply net can be 'reused' across domains (the -reuse option) so the same physical supply doesn't need to be redeclared at every level of hierarchy.
Example
In one example, three sibling power domains PDA/PDB/PDC each get their own PVDD/GND supply ports at the top level, tied down to shared top-level nets like PVDDTop1/2/3, with a shared GND_NET used across all three.
Why It Matters
Getting supply nets/ports right is foundational — set_domain_supply_net (which designates the primary power/ground net for a domain) and every later strategy (isolation, level shifting, retention) all reference these supply nets by name.
Command
create_supply_port -domain
create_supply_net -domain [-reuse]
connect_supply_net -ports {list}Common Beginner Mistake
A beginner mistake is creating a new supply net at every level of hierarchy instead of reusing one with -reuse, which needlessly duplicates supply objects that should really be the same physical rail.
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