What's PR got to do with it?
Ed Lee has been around EDA since before it was called EDA. He cut his teeth doing Public Relations with Valid, Cadence, Mentor, ECAD, VLSI, AMI and a host of others. And he has introduced more than three dozen EDA startups, ranging from the first commercial IP company to the latest statistical … More »
Stale IP – another view
November 26th, 2012 by Ed Lee
Liz: Manoj, what is stale IP?
Manoj: An IP may become stale because either its specifications have changed (e.g., USB 1.0 vs. 2.0 vs. 3.0) or there is a better implementation available (e.g., a graphics core is now running at 800Mhz instead of 500Mhz). Typically, people will use the latest version, and the older versions are no longer used. So the stale IPs in this case will die a natural death. What is more challenging, however, is a specific IP developed for a specific project and, over time, no other project used it. So the IP becomes stale. Most of my answers will apply to this type of stale IP.
Liz: What’s so bad about it?
Manoj: The main issue with a stale IP is the fact that nobody really knows the details about it. If I were to use that IP, I would be putting my design at risk because I am now adding some logic to my design for which I don’t have all the information and can’t find anyone who can provide that information either.
Liz: How do we prevent it from being stale?
Manoj: One of the key things that can be done to prevent IP from going stale is to document the IP. I don’t know how many people still remember the TTL datasheets but when you looked at the datasheet, you got complete visibility into what that component did. The same concept can be applied to present day IPs, where you document various characteristics of the IP. For a hard IP, this may be the timing characteristics, physical profile, etc. while for a soft IP this may be timing constraints, clock domain information, testability profile and power profile.
Liz: What are you supposed to do with it?
Manoj: A stale IP will just sit in the library with nobody really willing to use it. So there are two things that you can do. One option is to catalog it so that it becomes usable. Doing this means spending time and resources to do some forensic work to create a catalog for these IPs. If this route is not viable, then the IP should be removed.
Liz: Why can’t you just leave it in your library?
Manoj: Leaving a stale IP in the library is just like leaving a book on designing Integrated Circuits from 1970s on your bookshelf. That may be an interesting read from a historical perspective, but has no real use today. What this does is take shelf space and might even mislead some people into thinking that this is how ICs are designed today. In the context of stale IP, the biggest risk of leaving it in the library is that someone might pick up the IP in their design leading to issues downstream. It also makes searching for the right IP more difficult since the search results may be overwhelmed by stale IP.
Liz: Is there a secondary market for stale IP?
Manoj: I don’t think there is a real secondary market for stale IPs. Hard IPs are tied to the process, and as designs move to new process nodes the IPs in the old process node are no longer needed. Soft IPs are potentially reusable but they need to be cataloged.
NOTE: Lee PR does work for Atrenta