It's TI's OMAP vs. STM's Nomadik in mobile iAs

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(02/05/03, 01:33:07 AM EDT)

Dallas, Texas -- Texas Instruments Inc. and STMicroelectronics have entered into combat for the potentially lucrative multimedia wireless and mobile Internet-centric computing and communications appliance (iAppliance) markets, both with ARM926TEJ-based applications processors at the core of their designs.

Dogged by handset cost, size and power consumption concerns; fumbled 3G rollouts; and a dearth of "sticky" applications, the midrange- to high-end markets for phones and PDAs have not been the stellar performers many had predicted. Professional-oriented PDA sales have stalled, with low expectations for much growth this year beyond last year's 12 million units.

"Everyone's talking about data taking off, but it's been slow," said Allen Nogee, a wireless analyst with Cahners In-Stat. "Voice is still the target market, and the good news there is that carriers are seeing their ARPU [average revenue per user] rising lately."

Recognizing the fetal state of high-end applications, both TI and ST are emphasizing the low-end to midrange intelligent- and smart-phone markets in their rollouts with iA-based designs which combine features of both phones and computing devices, although neither approach excludes high-end PDAs. Both processor rollouts emphasize low power consumption.

The new parts in TI's quiver expand on its well-established OMAP 710 smart digital baseband and 1510 applications processors, based on an ARM RISC and C5X DSP combination architecture. The new lineup sticks with the C55 DSP but shifts from an ARM925 to a 200-MHz ARM926TEJ with Java acceleration and V5 multimedia enhancements.

Along with some 40 integrated peripherals and multimedia support options, TI added hardware encryption support that can speed encryption by a factor of 90 and hashing by a factor of 30, depending on the data stream rates, said Mike Yonker, chief technologist of TI's wireless computing group. The hardware handles SHA-1/MD-5, DES and 3DES encryption.

The lineup starts with the Omap 730 and 732, for smart-phone applications. The 730 uses an ARM7TDMI embedded processor and a C54X DSP to implement a GSM/GPRS Class 12 digital baseband. It also offers a 5-bit 54-Mbit/second wireless-LAN interface. Applications are handled by the separate, 200-MHz ARM926TEJ. The 732 adds up to 256 Mbytes of stacked mobile synchronous DRAM.

For multimedia applications processing on higher-end phones and PDAs, the Omap 1610 is based on the ARM926TEJ and a 200-MHz C55X DSP. The 1611 adds SRAM as well as the 54-Mbit WLAN interface option. The 1612 adds 256 Mbits of stacked, low-power double-data-rate memory. "The 730 is a smart-phone processor for GSM/GPRS, but some are even looking at it for low-power PDAs, so we're blurring the line between the smart phone and the high-end feature phone," said Yonker.

Gaining traction

STMicroelectronics, meanwhile, enters the markets as somewhat of an underdog, having let TI and Intel (with the Xscale processor) garner much of the applications-processor market over the last year, especially in Asia. But according to Richard Chesson, ST's director of business development for America, the company has clocked a short history in applications processors via the ARM920-based STA2001, which he said has gained traction in Taiwan. "We also have a strong cell-phone business with which we've established good relationships with companies like Nokia," he said, "and that's the market we're going after."

ST's Nomadik17 is similar to TI's Omap in that it adheres to a hybrid approach (based on homegrown DSP and the RISC ARM926TEJ) and offers a stacked-memory option (based on flash). It lacks hardware encryption and has fewer peripherals than TI's lineup. But Chesson said the target was power savings.

To that end, ST chose to go with a faster 350-MHz ARM processor and a dual-DSP "smart accelerator" approach - one DSP each for video and audio processing. The DSPs are ST's MMDSP+ 24-bit very long-instruction-word devices, running at 200 MHz. Chesson claimed ST's distributed approach differs from similar offerings in the degree to which it decouples the ARM from the coprocessors, thereby limiting CPU loading.

While a DSP is used for video, many of the classic MPEG compression/decompression functions, such as discrete cosine transforms, are done in hardware. "To decode a 15-frame/second MPEG-4 video stream at QCIF resolution and in parallel doing MPEG-3 audio decoding, our consumption estimates are under 20 mW," Chesson said.

Other power-management features include a 1.2-volt core, a fast crossbar bus with an enhanced DMA structure, clock gating and a finer 0.13-micron geometry implemented ST's low-leakage HCMOS9 process. The processor will come out of the gate with support for MPEG-4 and H.263, with H.264 codec support expected next year. It will also comply with the Open Mobile Application Processor Interface (OMAPI) standard that ST jointly announced with TI in December.

Power consumption also figured into TI's design, said Yonker. The techniques incorporated into the new lineup yield a 10x reduction in current draw during deep-sleep mode, "down to 10 microamps." The TI lineup is implemented in a 0.13-micron process. It maintains the real-time clock but can lower the voltage going to the ARM and DSP; split power rails allow the DSP to be completely shut down and not take any leakage when not in use. The number of power-sucking oscillators was cut from four to two.

On the tool front, Chesson said the Nomadik17's C compiler virtually eliminates assembly-language programming. "TI DSPs have great tools, but you're programming in assembler [with the implied difficulty and lack of portability]," he said. "We have a pretty good idea who's shipping 100 percent C-programmed code and who isn't, and all our audio products are programmed in C."

But Jeff Bier of Berkeley Design Technology Inc., an independent DSP technology analysis firm, said he would "be very skeptical of such claims. It isn't accurate to say that C5000 software developers rely mainly on assembly code.

"Getting efficient audio and video software nearly always requires handcrafting the code in some way. Many developers do this by rewriting a few critical inner loops in assembly. With a good C compiler, you can sometimes get a similar result by manipulating the C code. But then what you've done is create C code that is crafted for a specific target processor, which isn't a whole lot different from writing assembly code," Bier said.

Both the ST and TI processors come in at the sub-$20 mark. ST expects to sample this summer and be in production by summer 2004. TI will sample the Omap1610, Omap1611 and Omap730 processors this quarter, and the Omap1612 and Omap732 processors with stacked memory in the second quarter; all five will be in production by the fourth quarter of this year.

Go to www.ti.com or eu.st.com for more information on these products.

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