Is there a way to constrain max skew between some path ? (and ideally do some bulk grouping). So say I have a bunch of instances

sub[N-1:0]

with

a_in

/

b_in

input ports and

a_out

/

b_out

output ports and they're all chained

a[N-1:0]

an

b[N-1:0]

. Is there a way to write a SDC so that the delay from

a_out

to the next block

a_in

and the delay from

b_out

to the next block

b_in

are within some margin of each other ?

industry does in various ways....mainly for source synchronous interfaces....you can use set_max_delay /set_min_delay which are easiest to use....Check if openlane supports it...

When I worked at Intel I added this non SDC extension to the timer. https://www.intel.com/content/www/us/en/docs/programmable/683243/21-3/maximum-skew-set-max-skew.html