Lightening The Information Overload

Compressing the power optimization time has become critical for design teams.


We live in an age where it’s very easy to suffer from information overload — even when that information leads to better designs.

Power optimization tools have been very well received in the market, with almost every major electronics company using these tools and seeing the benefits. Yet, if a power optimization tool shows you everything you can do to improve your design, it’s too much; there’s not enough time in your schedule to do all of that. After all, if you’re a smart phone, tablet, wireless device, or digital camera maker, you’ve got six months to get your design out the door.

There is a real stress on fast turnaround. So they want quick feedback, they want quick turnaround, and they want automation. Even if they want to explore, they want guidance on where to explore. And they don’t want to verify the changes made by an automated tool, because it takes weeks to finish verification through simulation. They want an automated flow that cuts down on re-simulation because re-simulation is a big headache. All of these things point to the need for compressing the whole power optimization time into as small a time as possible while at the same time providing the biggest bang for the buck.

Part of the problem is that it’s difficult to know where to focus your optimization effort, even when you employ a power optimization tool. So the feedback we’ve gotten from our customers is that they really want to focus on areas where they should be focusing. They want pointed feedback on where in their designs they are actually wasting a lot of power.

They want automation to help them out with the biggest gains in the smallest time.

With this kind of feedback customers are now warming up to the idea of using an automated power optimization tool, making changes to the RTL, and being able to verify those changes through an automated equivalency checker because it really cuts down their turnaround time. The benefits are enormous.

We can see this by comparing a manual power optimization approach to an automated one that includes high level synthesis and equivalency checking; such as that found in the Calypto Catapult LP/SLEC flow. In the manual approach, designers had to spend six or nine months to achieve a certain level of power savings. The Catapult LP automated flow is able to provide the same degree of power savings or better in a matter of days, with the tool doing the optimizations, generating a new design, and verifying the equivalence of the new design versus the original. Obviously, this is a huge productivity improvement.

We now provide this entire flow very early in the design cycle. The Catapult LP flow makes it possible to quickly identify the regions of the design to work on; analyze power internally; find the hot spots and the regions where power is being wasted; automatically figure out what is the best strategy to save power, and then generate a new design that is functionally correct and fits into the synthesis and implementation flows.

Users of this automated flow don’t have to learn about the power optimizations because these have been developed already. For the same reason, they don’t have to rely on their knowledge of the design. They just run the tool, and then let it do the optimizations. And they have confidence that it has done the best optimizations possible, and beyond this the designer cannot do anything more to improve upon that. Once the RTL has been built, they can accept it as a sign off for power because the new RTL has been verified to be functionally correct. For the designers who want manual control, PowerPro points them to the right places in the design to optimize for power so that they do not have to waste time in figuring out where power is being wasted.

Initially, it was a surprising discovery for us when we talked to camera makers and wireless and smart phone companies to learn that they were not putting a lot of effort into optimizing for power. The reason for this was that unfocused optimization adds weeks to their schedules. But now they have a tool that can compress everything and deliver functionally correct, power optimized RTL, so they can start optimizing for power without having to compromise on time-to-market. Instead of getting bogged down by an information overload, they can put their design flow into overdrive.