IBM will steer PowerPC into mobile mart

The company also is stepping up its efforts in embedded Linux, adding it to the PowerPC brew to entice customers looking to differentiate their products on performance.

Kelly said IBM believes the fastest-growing part of the semiconductor industry will be mobile devices that combine computing and communications functions. The company calls the concept pervasive computing.

"The volumes and revenue going forward are going to be in PDAs, handsets, in- cab [telematics] in automobiles, game machines and other systems that are power-sensitive," he said. "We have hundreds of people working now on low-power solutions and are making some very big investments in this area. We gained early ground by taking the PowerPC into the game machine space with Nintendo and Sony, and now we want to extend that to battery-operated systems."

Kelly, who is in charge of IBM's semiconductor and storage divisions, acknowledged that "ARM and MIPS are the clear incumbents in the low-power space" but questioned "whether they have the wherewithal to continue to extend those architectures."

Low-power design "is not a static thing, and you need to make big investments," he said. "These architectures are not easy to sustain. I think eventually it will come down to two or maybe three big companies, including Intel and IBM."

If the embedded-Linux strategy plays out, IBM may also take on Microsoft Corp., which has seen growing success with its PocketPC operating sy stem in the PDA market. IBM has surprised many by successfully advancing Linux in servers, creating an intense competition with Microsoft. Kelly said IBM's internal efforts to further the embedded Linux operating system are bearing fruit.

"The whole OS portion of this market is in flux, and we think eventually that embedded Linux on a PowerPC will be a big play in this space," he said.

Fork in the road

IBM isn't daunted by the fact that many cell-phone vendors have developed an installed base of code based on ARM processors, Kelly said. As the cell phone and the PDA "merge into a single device, systems companies will be forced to rewrite their source code. That creates a fork in the road," making it easier for IBM to gain entry to a cell-phone market that has been dominated by Texas Instruments, Motorola and others with strong DSP technology.

While IBM has a license to the ARM7 core from ARM Ltd. (Cambridge, U.K.), Kelly said his company has yet to decide whether it will license the ARM9 core. In the DSP area, IBM licensed the ZSP core, owned by LSI Logic Corp., largely because some customers had requested it.

"I have not invested heavily in signal processing, because in the long run we believe the general-purpose processor will take on most of the workload," Kelly said. "As the cell phone and the PDA merge, the CPU will take on the computer-like functions. Historically, DSPs have been very good at specific algorithms where there is a lot of parallelism — for algorithms that are optimized for very specific signal-processing functions. That will change."

IBM has learned quite a bit about power conservation from its experience engineering the Thinkpad notebooks. Much of the power savings for that platform in recent years has come at the system level, via progress in such areas as learning when to instruct circuits to turn off and other power-saving tricks. Through its work on game systems with Nintendo Ltd. (Kyoto, Japan) and Sony Corp. (Tokyo), IBM has learned tricks to cut power at both the chip and system levels, Kelly said.

Numbers game

Still, IBM has its work cut out for it, said microcontroller and DSP analyst Tom Starnes at Gartner Dataquest. "Intel has a big advantage in the PDA market. The PocketPC operating system is at a pretty good level now; it's the OS of choice for the upscale PDA market. As far as I know, Microsoft only supports the ARM architecture," which Intel supports with its StrongARM and Xscale products, Starnes said.

IBM's strategy for embedded Linux also would have to take into account the desire of many users to exchange files between a PDA and a desktop. "That makes it more of a challenge for IBM. In the end, it comes down to a numbers game," Starnes said. "The application developers will support the platform — whether it's Palm, PocketPC or Linux — that has the most target platforms."

IBM "right now doesn't have a lot of traction in either the PDA or the cell-phone markets, " said Will Strauss, president of research firm Forward Concepts (Tempe, Ariz.). "The PowerPC has no play there at all right now. But IBM has the kind of worldwide reputation that gets them in the door for a hearing just about anywhere."

Nonetheless, Strauss said, IBM's heritage has been in the high-performance and high-cost end of the semiconductor market. "Can IBM slug it out in what may be a commodity market? They are not known to have the lowest-priced fabs in the industry, because they were creating ICs that went into systems that sold for millions of dollars a copy. Maybe we are looking at a new IBM."

Power mantra

For many IBM chip designs thus far, Kelly acknowledged, the goal has been to keep power consumption just below the acceptable threshold, delivering the best-possible performance at the given power budget. And the PowerPC has been known for its use in performance-driven applications, such as IBM servers, Apple Computer systems and the high-end ASICs used larg ely in the networking industry.

Now, the push is on throughout IBM's engineering staff to reduce power consumption across the board, from development of such process technologies as silicon-on-insulator to computer architecture design and system-level engineering.

For example, the PowerPC 405LP will leverage IBM's efforts in voice recognition by including an on-board hardware accelerator for speech recognition, as well as accelerators for triple DES cryptography and instruction stream decompression. The hardwired accelerators consume less power than if the same functions were handled by the 32-bit PowerPC core, said Gary Carpenter, chief architect of the 405LP.

Carpenter said the design goal for the 405LP was to hit a power budget that would start at half a watt and move down to 50 to 60 mW of active power dissipation.

"We set out to enable voltage scaling on the fly, without having to relock the PLLs [phase-locked loops]," he said. "The idea is that the application can deter mine what the optimum performance and power trade-offs can be.

"That [trade-off determination] could come from the demands of the application or from how much energy is left in your battery. We think we can move the whole debate about power consumption to a pretty high level," Carpenter said.

The 405LP operates at 1 volt to 1.8 V. Carpenter said system designers can choose to vary the frequency of the processor as needed, from a scant 11 MHz to the maximum of 380 MHz.

"Customers can be as aggressive as they want to be," he said. "We see the future being one of significantly varying performance, particularly with the improved user interfaces, such as natural-language speech recognition, handwriting recognition and retinal scans. If a person is running an MPEG-4 video, the system will move up in voltage.