Zucotto samples Xpresso Java processor

Zucotto samples Xpresso Java processor
By Loring Wirbel, EE Times
September 12, 2000 (5:39 p.m. EST)
URL: http://www.eetimes.com/story/OEG20000912S0066

LA JOLLA, Calif. — Zucotto Wireless Inc. is sampling a Java processor that links handheld PDAs or digital cellular phones with broadband access systems and basestations. The Xpresso processor is a Java Virtual Machine implemented in hardware, with 16 kbytes of internal cache and a dedicated memory management unit.

The sampling of the device fulfills a promise Zucotto made at the Wireless 2000 show in February. Mark Wells, president and chief executive officer at Zucotto, said the biggest surprise of the past six months is the lack of competitors offering Java processors for wireless applications. Several processor developers that had initially shown interest in Sun Microsystems Inc.'s portable language have been diverted by the Wireless Applications Protocol (WAP) and the limited possibilities of linking WAP and Bluetooth.

"We've had quite a few handset manufacturers come to us in a sudden panic in the last few months," Wells said. "There i s a growing realization that WAP can't scale for many wireless networks."

Zucotto's long-term goal is to offer synthesizable intellectual-property cores to external semiconductor manufacturers, but for the time being, the company will produce its own Xpresso chips. It also will offer Whiteboard, a simple development platform with Win32 simulation, and Xpressoboard, a full-featured board with keypad and display, to help developers come up with unique applications for creating wireless networks using Java.

The Xpresso processor has not changed significantly from early designs. It has dynamic variable clocking from 5 MHz to a full-system clock rate, adjustable in 1-MHz increments, which allows each circuit block to use the lowest power possible.

Audio addition

On-chip blocks include dual UARTs, a parallel host processor interface and a Bluetooth baseband block. The one addition made to the chip since early simulation, Wells said, was support for 16-bit audio, since high-end audio was becoming a standard feature of so many handheld devices.

Instead of a real-time operating system, Xpresso uses a software layer — Slice, for service layer in consumer electronics — which binds Java applications to hardware operations. The Connected Limited Device Configuration spec is used as an API to bring in new applications, which later can be moved into direct silicon support.

For example, Zucotto has signed a deal with Packet Video Inc. (San Diego) to add that company's MPEG-4 video support through APIs. Packet Video algorithms could be implemented in hardware in later versions of Xpresso. Wells said that the company will make similar extensions in graphics and security processing.

The two board-level options of development tools, Whiteboard and Xpressoboard, are part of a development environment Zucotto calls Jacknife. Whiteboard, with a device emulator, might be used in the early stages of developing applications, and it can be shipped with Bluetooth communication boards. The Xp ressoboard, with an Xpresso processor and a comprehensive set of hardware peripherals, is used when applications are closer to active prototyping.

Zucotto emphasizes the Jini language, particularly a second-generation Jini optimized for wireless devices, as a key to making its processor more useful for service-discovery operations, specifically with handhelds that have an active Bluetooth link. Zucotto programmers are among the primary authors of a new extension to Jini, "Surrogate Jini," which will be a lighter-weight language used in many cellular phones and PDAs.

"The usefulness goes far beyond connectivity to the Internet," said Wells. "We're getting unexpectedly strong interest from automotive manufacturers, as well as the gaming industry."

The company has augmented its initial research centers in San Diego and Ottawa with a development facility in Copenhagen and sales and field engineering offices in Korea and Japan. That helps to drive designs of second-generation processors for regionali zed 3G phone markets, Wells said.

Showing why Java and Jini represent ideal messaging protocols for wireless, and why an efficient Java engine should be implemented in a hardwired processor instead of a programmable block in a larger host remain the biggest tasks, Wells said. Zucotto is not out to replace host controller or baseband DSP functions, Wells said, but to accelerate Java-specific communications in cellular and Bluetooth applications.

"The first step is in making sure the customer gets it at a fundamental level," Wells said. "But you also have to convince them that an efficient Java Virtual Machine simply can't be implemented in software."