Copy Protection Remains A Big Issue As Chip Grabs Spotlight At Show

Micronas Spins Next-Generation Silicon For MP3 Players

27-Mar-00

In an effort to maintain its market dominance in MP3 decoder chips, Micronas Semiconductor (Freiburg, Germany) has rolled out its next-generation silicon for MP3 players. The MAS3509F, unveiled at the recent CeBIT show, is based on the company's homegrown DSP, integrated with an A/D and a D/A converter on a single chip. The chip supports the Secure Digital (SD) flash card standard promulgated by Matsushita, Toshiba and SanDisk. Micronas is hoping that feature will provide an adequate route to supporting the Secure Digital Music Initiative (SDMI) specifications, still in development. With audio codec and copy protection issues still largely unsettled in the Internet music player market, Micronas' embrace of the SD card format may herald a trend among chip makers: riding the SD card to SDMI compliance. Hubertus von Janecek, Marketing Manager for Advanced Audio at Micronas, said he was confident that the SD card would become the preferred means of providing SDMI compliance. ""Twenty-five telecommunications and automotive companies have now committed to support the SD Card Association,"" he said. Separately, STMicroelectronics has launched its own next-generation MP3 decoder. The STA015 chip is based on the very long instruction word (VLIW) DSP used in the company's established STA013 MP3 decoder. MP3 PioneerMicronas pioneered the MP3 silicon market and claims it had a worldwide market share of 90 percent last year. The company said it has shipped 2 million MP3 chip sets. Micronas' silicon takes a different approach from competitors such as Cirrus Logic and Texas Instruments. The German company has opted not to incorporate a microprocessor or microcontroller in its single-chip solution and is continuing to advance its application-specific DSP architecture as a superior alternative to more general-purpose DSP engines. ""The microcontroller is the area where equipment companies differentiate themselves,"" said von Janecek. ""Our DSP is highly specific to audio codecs. In our previous generation, the MAS3507D chip set in 0.5-micron CMOS, we were 20 percent smaller in chip size than the competition in 0.25-micron, and 20 to 30 percent lower in power consumption."" Von Janecek acknowledged that competing solutions combining an ARM core with DSP, for example, could offer ""a huge flexibility"" advantage in terms of ability to process a variety of codecs. But ""we do not believe that the race [for the MP3 market] is in the number of audio codecs the chip can handle,"" he said. ""We've solely focused on the cost and low power consumption requirements"" imposed by affordable consumer MP3 devices. The DSP core on the MAS3509F is designed to process MP3 and MPEG Advanced Audio Codec (AAC). Support for Microsoft Corp.'s Windows Media will follow in the third quarter, according to Micronas. By separating a microprocessor from its solution, ""our chip can be used with any types of microcontroller or RISC microprocessor, ranging from 4-bit to 32-bit"" devices, said von Janecek. OEMs can choose what they believe is the most suitable microcontroller, in accordance with system design decisions on ""displays or no displays, different memory types and a method of up- and downloading files,"" he added. An OEM system, for example, can be designed to feature ""a USB cable or a mobile phone plug-in, to download music files."" Decisions on watermarking and encryption methods now being discussed within the Secure Digital Music Initiative group affect whether Micronas, or any other silicon vendor, can claim their chips comply with SDMI's upcoming copy protection requirements. Micronas, however, tipped what some observers see as a growing trend in the industry: an assumption that it's possible to achieve SDMI compliance via direct support for the Secure Digital card. Indeed, Micronas is rallying around the decryption and authentication methods incorporated in the SD card spec as a security feature, rather than waiting for SDMI to finish its work. The SD card is based on the Multimedia Card removable solid-state memory format, originally pioneered by SanDisk and Siemens, with the proposed addition of security features. ""Judging from the current version of the SD card spec we have today, we believe that our chip can handle both decryption and authentication methods designed for [it],"" von Janecek said. At a time when the SDMI is still working on the final text of a call for proposals for watermarking technologies for its Phase II screening, there is no assurance that SDMI members will agree on the SD card's security method. A Trojan Horse? However, those who developed a new encryption method for the DVD-Audio standard appear to be using the SD card as a Trojan horse to have their encryption system recognized as a preferred copy protection system for SDMI-based Internet music players. Meanwhile, a key feature of Micronas' new chip is low power consumption. The company has integrated an additional two dc/dc converters so that the chip can run on 2 volts while other components within a system, such as microcontroller and flash memory, can synchronously run at 3.3V. The company maintains that the high-level integration should ""allow OEMs to produce cheaper and smaller MP3 devices, including products like MP3 mobile phones and wristwatches,"" since they can now run on one battery. The chip runs on 65 milliwatts. Its predecessor, without a D/A converter on board, required 86mW. Manufactured in Germany using a 0.5-micron mixed-signal CMOS process technology, the MAS3509F is sampling now. It will be priced at less than $10 when it goes into volume production this summer. For its part, STMicroelectronics has announced an MP3 audio decoder chip that also includes an embedded adaptive differential pulse-code modulation codec to allow voice recording and playback.Source: EE Times