Friday, May 26, 2006

Cadence / Spectre Bug

I just had to post this because it took me two days to realize this problem. I'll post just in case somebody will run across it that it may spare them the same trouble that I went through. Anyways, I was running s-parameter simulations using Cadence spectre and the analogLib. I was getting frustrated with spectre because I wouldn't change any circuit values but the simulation results were drastically different!!! This make no sense! Well, I finally figured out that in the s-parameter simulation form it makes a big difference with the ORDER you type the port values in the form. Looking at the image... You have to type the input port first (in my case /PORT0) and then the output port (/PORT1 in my case). The noise analysis section specifies the input port and the output port, but no indication is given that the order matters in the s-parameter analysis section, BUT IT DOES!!! Again, specify the name of your input port first. Don't make my mistake.