Noting that CEVA, Tensilica and ARC have recently launched radically new DSP-specific architectures, I began to wonder if the traditional DSP chip suppliers, Texas Instruments, Analog Devices, Freescale, LSI and NEC have been as aggressive in their recent offerings. I don't mean to infer that the licensable IP cores are better than those of the DSP silicon vendors, but there is the perception is that the licensing folks are more aggressive in introducing new and novel architectures.
TI continues to rollout new DSP chips, but they are based substantially on shrinking geometries, adding more features, accelerators or more memory and I/O to legacy architectures. Of course, TI's mantra has always been "code compatibility," so maybe that's not a bad approach. Freescale seems to be frozen in time on its base 16-bit DSP architecture, although the company has provided some remarkable additions for its heavy-duty, StarCore quad-core infrastructure chips. For basic DSP needs, the company seems to have made more progress in beefing up its legacy 32-bit Coldfire RISC product line with DSP capability. But that's bolting on features to an architecture that harkens back to the Motorola 68000 (c.1979).
Analog Devices still ships its older 16/24-bit DSP chips, but current emphasis is on the 32-bit SHARC and 16-bit Blackfin product lines. Although worthy and popular products, most of the catalog entries are simply variants of the original architectures. LSI through its legacy StarCore product line continues to emphasize cellular infrastructure and media gateways through providing multicore solutions. NEC's Medity DSP family has been applied to 3G cellphone basebands, but the company appears to be committed to employing Tensilica's licensed Xtensa LX2 DSP architecture in future(multicore) LTE basebands.
NEC's selection of Tensilica's DSP IP is notable in that NEC was the first company to introduce a commercially viable DSP chip (the uPD7720 in 1980) and has continued producing even more advanced DSP chips ever since (mostly for Japanese and European markets). Building on the Xtensa success, in Mid-June, Tensilica announced its ConnX DSP product line. With its unique configurable instruction set, Tensilica has morphed its basic Xtensa RISC architecture to become an even more compelling DSP engine. For LTE and 4G cellular SoC designs, Tensilica has introduced the ConnX BBE (Baseband Engine) for which the company has added over 200 baseband-specific instructions. None of the traditional DSP chip suppliers can make a similar claim.
In early 2009, CEVA announced its new CEVA-XC DSP core. The powerful new core builds upon the architecture of the CEVA-X DSP (now shipping in high volume 3G cellphones) by incorporating up to four modular vector units into the CEVA-X framework to deliver processing power of up to 200 billion operations per second. This scalable performance level enables CEVA-XC architecture to support both LTE/WiMAX low-power cellphones and macro base stations.
ARC has taken a different tact, adding multiple SIMD engines to its configurable cores to provide a compatible range of configurable 32-bit processors that offer both RISC and full performance DSP capabilities in a unified architecture. They range from the world's smallest, lowest power licensable 32-bit core to a full-featured host processor that is said to deliver over 1000 DMIPS of performance. The company's "Sound to Silicon" market thrust keeps it out of the bruising cellular baseband market.
I'm sure each DSP chip company mentioned will take umbrage that their DSP architectures haven't been advancing, but perception is often reality.
Will Strauss is the President of market researcher Forward Concepts (www.fwdconcepts.com).