Automotive Signal Processing

Audi Engineers Turn to Blackfin and Sharc Processors for the Audi A5 In-Vehicle Audio Subsystem

Media formats and communications standards are in a constant state of change. When Audi engineers were designing in-vehicle audio subsystems for the A5, they needed an exceptional level of performance and connectivity to handle audio decoding, DAB processing, and MMI control within the A5's multitude of automotive infotainment system offerings. In addition, audio required scalability, field upgrade ability, and the software flexibility for a variety of signal processing, control processing, and multimedia support requirements.


Audi considered other processor architectures, but Blackfin was found to be ideal as it offered the supporting infrastructure to enable fast, low risk development. ADI's reputation as a leader in high end audio system technology also helped to influence the decision as did the company's extensive portfolio of industry-specific third-party intellectual property.

Audi A5

Audi A5 Design-In

The Audi A5 is a classic sport-styled coupe featuring sculpted bodywork and aerodynamic lines. The harmonious design of the car's interior and its precise instrument panel, which is fully integrated into the dashboard, complement the vehicle's athletic exterior.

Thanks to Blackfin processors and other components from ADI, the head unit radio subsystem, with its graphical multimedia interface (MMI) dashboard display, makes certain that the car's inner harmony truly resonates with its classic exterior excellence.

Software-Defined Radio: Blackfin Processor

The 533 MHz ADSP-BF539 Blackfin processor controls the Audi symphony/concert radio's MMI via the processor's parallel peripheral interface port. The MMI was developed with a state- of-the-art software tool for designing graphical user interfaces. This tool enabled the designers to produce a prototype of the MMI user interface and to easily explore additional customization. An optional digital audio broadcast (DAB) feature is powered by a separate ADSP-BF532 Blackfin processor. Because the Audi symphony/concert radio is designed as a software-defined radio (SDR), Audi can implement new radio protocols easily through software updates. Future upgrades will require only a software flash of new IP to the Blackfin's programmable hardware.

Integrated Multimedia Systems: Blackfin Processor

A Blackfin ADSP-BF532 processor was used in the CD player, a product used in other Audi vehicles, to handle MP3 decode, playback, and audio processing. This Blackfin processor also connects to the media oriented system transport (MOST), a bus widely acknowledged as the network of choice for integrated automotive multimedia systems. The ADSP-BF532 runs MOST network stacks and protocol, and connects via the Blackfin serial bus.

Music Interface: Blackfin Processor

ADI's ADSP-BF532 Blackfin processor also powers the Audi music interface. At 400 MHz, the processor features the right price and performance for this application, and the fact that the processor can perform both control and signal processing allows it to handle both audio processing and external device management. The Audi music interface enables users to control stereo audio sources, including USB sticks and iPod® devices (generation four and later) through the audio system and multifunction steering wheel. The interface also replicates the iPod display, including track titles, on the audio screen.

Take advantage of ADI's free Blackfin online learning and development (BOLD) video tutorials at These videos are a convenient and effective way for engineers to become more familiar with the methods and techniques used in applications that integrate the Blackfin embedded processor.

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