Five-Minute Tutorial: Avoid SI Problems With Better Pin Placement In Encounter Digital Implementation (EDI)

I know we're over halfway through January already (where does the time go?), but Happy New Year everyone! I hope 2012 is a good one for your business and your chip designs, and let's hope the Mayans just ran out of ink when they were finishing the calendar for this year.

Today I'd like to highlight an option of the assignPtnPin command that was added in Encounter Digital Implementation System (EDI) 10.1. This option is called -improveSI. Sounds intriguing and helpful, right? Let's see how it works:

If you use the command assignPtnPin -improveSI, then the pin assignment will attempt to place pins such that pins on the same layer are not on adjacent tracks. Also the pin assignment will attempt to place pins such that you don't have pins on top of each other in consecutive preferred-direction layers.

For example, if one pin is placed in M4, then the -improveSI option will attempt not to place another M4 pin on the closest track to either side of the first pin, and will also attempt not to place an M6 or M2 pin in the same spot as the original M4 pin.

I keep saying "attempt" because I'm guessing that legal placement will trump -improveSI, so if you have lots of pins on a small block, or have strict limits on pin layers, following the -improveSI rules may not always be possible.

I have not used this option myself yet, so give it a try and report back how you like it!

Here are some other tips to avoid SI problems:

Five-Minute Tutorial: Fixing SI Victim Nets

Five-Minute Tutorial: Setting Up Clock Routing Rules

- Kari Summers