These days , I found a strange phenomenon,this problem led me stop my work,so I would like to ask ,I paint diff_pair ,give a simple example
,each line through a capacitor ,a differential line through two capacitors.Assume the net in front of the capacitors are :IN_P,IN_N, the net behind
the capacitors are seted to be OUT_P,OUT_N, In schematic they were seted to be diff_pair ,general we want the two diff_pairs should be
independent,however,something happened,afer we set them to be th diff_pairs, OUT_P,OUT_IN will includ IN_P,IN_N, it means that IN_P
will inside in OUT_P, IN_N will inside in OUT_N, the nets OUT_P and IN_P look like the same one,the nets OUT_P and IN_P look like the same one too,
Then I use ANALOG seprate them from each other , and I want to see if I can set them independent, then strange things happened I can set the IN_P and IN_N into a differential pair,
but cannot set OUT_P and OUT_N to be a differential pair.
The tips is” the Electrical NET OUT_P OUT_N is a power net, and it cannot be used to creat the diff pair”. But surely they are not power net at all. What can I DO,Who can help me , thank you ~ ~ ~
Power nets in the constraint editor are set in Setup -> Settings -> Power and Grounds.
It automatically sets net to power if they are above a certain pincount (can be set in Setup -> Settings -> Electical nets at the front end CES) and I think also with ibis model pin types but never tried that.