markdown/gh_discussions/Query/3327.md

What is the order of pins for get_ports?

Tool: OpenSTA

Subcategory: Usage question

Conversation

oharboe

I'm using -group -order with set_io_constraints and I'm using the tcl snippet below to enumerate pins.

However, this brings up the question: what order does get_ports return pins in?

proc match_pins { regex } {
    set pins {}
    foreach pin [get_ports -regexp $regex] {
        lappend pins [get_property $pin name]
    }
    return $pins
}

oharboe

@nerriav FYI

maliberty

arbitrary order, no assumptions should be made

maliberty

The command comes from SDC and such an option would be non-standard and non-portable.

oharboe

In mock-array-big, I introduced a designs/asap7/mock-array-big/util.tcl function, which is shared between macros and top level of the design.

I'm thinking that a shared util.tcl function will be required for non-trivial designs anyway.

Perhaps it is sufficient to provide an example of this in mock-array-big for now?

I see this somewhat tying into how one would have a centralized method to calculate properties of macros and the top level design: manual placement of macros relative to eachother, sizes of macros calculated based on environment variables, etc.

https://github.com/The-OpenROAD-Project/OpenROAD-flow-scripts/discussions/1067