Posts Tagged ‘PowerPC’

Is IP a 4-letter Word ???

Friday, May 9th, 2008

As I’ve been thinking a lot about Intellectual Property (IP) lately, I recently recalled a consulting project that I had led several years ago … I think it was 2002. The client was designing a processor chip that had a PowerPC core and several peripherals. The core and some of the peripherals were purchased IP and our job was to help with the verification and synthesis of the chip.

Shaun was responsible for the verification. As he started to verify one of the interfaces, he started to uncover bugs in the associated peripheral, which was purchased IP. We contacted the IP provider and were told most assuredly that it had all been 100% verified and silicon proven. But we kept finding bugs. Eventually, faced with undeniable proof of the poor quality of their IP, they finally fessed up. It seems the designer responsible for verifying the design had left the company half way through the project. They never finished the verification. Ugh 1!

Meanwhile, Suzanne was helping with synthesis of the chip, including the PowerPC core. No matter what she did, she kept finding timing issues in the core. Eventually, she dug into the PowerPC core enough to figure out what was going on. Latches! They had used latches in order to meet timing. All well and good, but the timing constraints supplied with the design did not reflect any of that. Ugh 2!

About a week later, I was called to a meeting with Gus, who was the client’s project lead’s boss’s boss. As I walked into his office, he said something that I’ll never forget …

“I’m beginning to believe that IP is a 4-letter word”.

How true. Almost every IP I have every encountered, be it a complex mixed-signal hard IP block, a synthesizable processor core, an IO library … they all have issues. How can an industry survive when the majority of the products don’t work? Do you think the HDTV market would be around if more than half the TVs did not work? Or any market. Yet this is tolerated for IP.

That is not to say that some IP providers don’t take quality seriously. Synopsys learned it’s lesson many years ago when it came out with a PCI core that was a quality disaster. To their credit, they took failure as a learning opportunity, developed a robust reuse methodology along with Mentor Graphics, and reintroduced a PCI core that is still in use today.

Still … no IP is 100% perfect out-of-the-box. IP providers need to have a relationship and business model with their customers that encourages open sharing of design flaws. This is a two-way street. The IP provider must notify its customers when it finds bugs, and the customer must inform the IP provider when it finds bugs. As an example, Synopsys and many other reputable IP providers will inform customers of any design issue immediately, a transparency that I could have only prayed for from the company providing IP to my client. In return, they need their customers support by reporting design issues to them. Sounds simple, right?

Maybe not. I had another client who discovered during verification that there was a bug in a USB Host Controller IP. They had debugged and corrected the problem already, so I asked the project manager if they had informed the IP provider yet. He refused. The rationale? He wanted his competition to have the buggy design while he had the only fix!

We, as users, play a role because we have a responsibility to report bugs for the good of all of us using the product. Karen Bartleson talks about a similar situation with her luggage provider, where customers are encouraged to send back their broken luggage in order to help the company improve their luggage design. The luggage gets better and better as a result.

So, besides reporting bugs and choosing IP carefully, what else can we as designers do to drive IP quality. I have one idea. One day, when I have some free time, I’d like to start an independent organization that would objectively assess and grade IP. We’d take it though all the tools and flows and look at all the views, logical and physical, and come out with an assessment. This type of open grading system would encourage vendors to improve their IP and would allow us to make more informed choices rather than playing Russian Roulette.

I’m half inclined to start one today … anybody with me?

harry the ASIC guy