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We are all familiar with it. Every year, designs get faster, smaller, and more complicated. Whether your newest package has a towering stack of memory dies placed into a cavity or a few massive flip-chips with critical bus lanes between them, it never fails.
The database that represents that complex package is, itself, growing more complex. Co-design dies, flow planning bundles, via structures for fan out and shielding of critical nets, you name it. As a group, we continue to find ways to achieve more with less – more computing power from less power in less space.
How, then, do you ensure that your SiP Layout or Allegro Package Designer database is optimized to allow you to work as efficiently, as quickly, and as intelligently as possible? Keep reading, and we will walk you through some of the tools designed to help you, how and when to apply them, and what to think about when you are ready to start your next layout – or if you need to update a large design already in production.
Regardless of the database you are using, there are a few rules that apply that will always help you to get better performance from your tool. The same is true in the Cadence package design tools. What are the key tenets to make sure you consider whenever you start a new design, then?
Those are just six very common, but powerful, concepts to keep firmly in mind as you do your design work. If you are always planning ahead, you will be astounded at just how much faster you can work. A little patience and forethought go a long way!
It is all well and good to design things perfectly from the moment you type “new” on the command line to start a new layout. But, designs go through many iterations (and designers’ hands) in their lifetime. If you open a design and find that performance is much slower than what you think is reasonable, are there ways to determine what is causing the performance issues?
You bet there are! Whether you are using SiP Layout or Allegro Package Designer, the first two tools you should turn to are both in the Tools menu.
Run the Database Doctor’s Performance Advisor. This incredible tool will do a thorough check of your design and give you a detailed report of changes you may be able to make to improve your performance. While you’re here, go ahead and run a database check; it takes but a moment or two, and will ensure that there is nothing of concern that might be the cause of future troubles.
After running the database doctor, take a look through the Package Design Integrity list of rules. There are many checks here which you can selectively run. Not only will they alert you to things like missing voltage properties on your power nets, but they can also find potential manufacturing and quality issues like vias misaligned with pins and clines with small bends that aren’t necessary.
Running these two tools can help point you at many things that will slow you down. The time they take to run will almost certainly be less than the extra time you would spend working on your design without them.
Don’t forget: You can add your own checks to the Integrity Check list. So, if you have something you know happens frequently in your design flow, consider implementing your own rule to check and correct it. There are helpful resources in the online help pages which can get you started with writing integrity checks of your own.
Do you have something you do that you’ve found makes your work faster? Share it with us, and we’ll follow up this post with another in the future. Let others benefit from your knowledge. They will thank you for it! Or, if you have a suggestion for an integrity check, or just something you find frequently causes your designs to bog down, your Cadence customer support representative is anxious to hear from you so we can improve the tool.
Bill Acito Jr.