San Francisco -- Promising performance, cost and board space advantages, Freescale Semiconductor Inc. this week will launch a pair of dual-core 90-nanometer digital signal processors that support multiple high-definition audio standards, including DTS-HD, Dolby Digital+ and Dolby TrueHD. The Symphony DSP56720 and DSP56721 represent the first offerings in a new Freescale family of 24-bit audio processors targeting consumer home entertainment, automotive and professional-audio applications.
Whereas many high-performance audio products rely on multichip DSP implementations, Freescale (Austin, Texas) is billing the Symphony devices as single-chip solutions. They incorporate DSP56300 24-bit cores, which handle the latest decoding standards and advanced postprocessing on the same chip. Each core completes 200 Mips with a 200-MHz clock, enabling the devices to meet the performance requirements of HD audio standards.
The DSPs are targeted at applications that require high performance for audio processing, such as HD-DVD and Blu-ray Disc next-generation DVD players, home A/V receivers, car amplifiers and infotainment systems, professional audio-recording equipment, and musical instruments and amplifiers.
The DSP56720 and DSP56721 feature integrated memory, including on-chip 608k x 24-bit words of ROM and 248k x 24-bit words of RAM. With a large amount of built-in memory, the DSP56721 eliminates the need for external memory for most consumer applications, according to Freescale. The DSP56720 adds an external memory interface for audio applications that use external memory to accommodate long delays.
Both devices integrate an SPD/IF transceiver and a 10-channel asynchronous sample rate converter to reduce component cost, and a direct memory access controller that can support up to eight DMA channels per core.
The new DSPs are code-compatible with Freescale's existing 24-bit DSP solutions, simplifying the migration path for existing customers. Both devices incorporate the same plug-and-play software architecture found in the Freescale DSP563xx family and support standard audio decoders, providing the flexibility for designers to customize postprocessing algorithms. That's key, said Todd Benson, manager of Freescale's home consumer and distribution segment. "There are several customers out there who are doing that," Benson said, "and it's beneficial to both them and us."
Freescale, which plans to show off the new DSPs later this month at the Consumer Electronics Show in Las Vegas, said it is working on a new software development tool suite to support both the multicore DSP567xx family and the single-core DSP563xx family. The tool suite, projected to be available in the second quarter, will include an integrated development environment and a single debugger to target a hardware or software simulator. It will support parallel-port and USB command converters, according to the company.
Starting from its days as Motorola Inc.'s semiconductor unit prior to a 2004 spinoff, Freescale has a long history of providing audio DSPs. Symphony products have been around since 1987, when they hit the market as the first 24-bit DSPs.
The Freescale architecture is capable of supporting 48-bit calculations, Benson said, which is necessary only for a small percentage of the time in the targeted audio applications. Benson acknowledged that there are arguments in favor of both 24- and 32-bit architectures for audio DSPs, and said that consumers are likely to assume that 32-bit is better. But audiophiles like the Freescale-based solutions, he said.
"If you look at the people in the markets that really care about fidelity, they go with our architecture," Benson said. "If we were to look at the people that are most concerned about audio fidelity, like people doing $15,000 home theater systems, most of those people are doing that with our DSPs."
See related chart
