SAN FRANCISCO -- Sept. 28, 1998 -- Signaling an expansion into the emerging car audio DSP market, and reinforcing its overall leadership in audio electronics, Cirrus Logic Inc. (NASDAQ:CRUS) today announced the availability of a design kit that streamlines digital audio system development for car and consumer entertainment manufacturers. Unveiled at the Audio Engineering Society (AES) convention, the new CRD4912 design kit provides all the materials to design a digital audio processing system, including a board design featuring the Crystal® system-in-silicon (CS4912) audio chip, complete design documentation, and DSP microcode firmware packages for both car & consumer audio systems.

With the most comprehensive DSP solution for car audio sound processing and Dolby® Surround Pro Logic™ applications in consumer audio, the new Crystal design kit enables audio system manufacturers to quickly and easily transition from analog to digital signal processing (DSP) solutions. By harnessing the advantages of digital processing, manufacturers can deliver functionality and performance that would be impractical in analog circuitry, making new high quality car and home audio feature sets viable for mainstream consumer markets.

"As the leader in digital audio integrated circuits, audio DSP firmware, and mixed-signal design, we aim to leverage our expertise by expanding into new applications," said Terry Ritchie, Director of Marketing for Consumer and Professional Audio DSP at Cirrus Logic's Crystal Semiconductor Products Division. "We believe our highly-integrated, DSP-based audio will create a new price/performance standard for cost-sensitive car and consumer audio systems. By providing DSP software that is ready-to-use, our design kits overcome the typical barrier to implementing a DSP design, offering manufacturers a time-to-market and cost advantage."

Featured Chip CS4912

The design kit builds upon Cirrus Logic's innovative Crystal system-in-silicon audio solution, which integrates five previously separate components into a single-chip, including a 24-bit digital signal processor (DSP); RAM for program and data storage; a phase lock loop (PLL) clock generator; a digital audio transmitter port, and a stereo CD quality digital-to-analog converter (DAC). By combining the functionality previously found on separate components into a single-chip, the CS4912 significantly reduces board space, pin count, and assembly and test costs. These valuable cost and size reductions make Crystal DSP-audio affordable and practical, enabling higher-quality audio in auto, television and mini-component systems.

CRD4912 Offers A Variety Of Configurations

To support a variety of configurations and potential customer designs, the CRD4912 is equipped with a superset of the circuitry required for typical car or consumer audio applications. For example, the CRD4912 includes both the CS5331 stereo analog-to-digital converter (ADC) and the CS4222 codec. The CS4912 would typically be coupled with the CS5331 ADC to provide a system with two analog inputs and two analog outputs. However, for systems requiring two analog inputs and four analog outputs, the CS5331 ADC would be replaced with the CS4222 stereo codec. By including both of these devices, the CRD4912 allows designers to evaluate either configuration. The CRD4912 also includes the CS8412 S/PDIF digital audio receiver and the CS8402 digital audio transmitter. While these devices would not be utilized in a typical CS4912 design, they are included in the CRD4912 to allow a designer to evaluate the performance of the CS4912 and associated DSP firmware independently of the ADCs and DACs.

Programmable DSP Increases Functionality

In order to help simplify the design process, Cirrus offers several application firmware kits for the CRD4912, including a kit targeted at automotive audio processing applications, and a Dolby® Surround Pro Logic™ kit targeted at stereo television, hi-fi, and mini-component systems. These kits include firmware which can quickly and easily be loaded into the CS4912's on-chip program RAM, enabling designers to evaluate the functionality and performance of the CS4912 without the delay, cost or specialized expertise needed to generate the DSP microcode.

Specific features for the car audio kit include the following: crossover filters, graphic or parametric equalizer, dynamic range compression, noise gate, peak limiting, and multiple-speaker time delay. Specific features for the Dolby® Surround Pro Logic™ kit include support for different output speaker configurations, and a virtual surround capability for playback on two-speaker systems. Both packages include a PC-based graphic user interface (GUI) application for controlling the firmware from a personal computer. The PC-based GUI communicates with the CS4912 device through the CS4912's SPI control port using a standardized messaging protocol. In the final production design, an embedded microcontroller in the design may utilize the same messaging protocol, minimizing the CS4912 firmware design effort.

Enabling the Transition From Analog to Digital

By providing DSP-based audio processing, the CS4912 offers feature set advantages over analog solutions. For example, up until now, audio signal processing for car audio has been implemented primarily in the analog domain, and feature sets are typically limited due to the number of components required. Likewise, for consumer audio systems, effective virtual surround processing and high-quality multiple channel time delays are impractical to implement in analog circuitry, but become viable when offered as digital solutions. The system-level integration provided by the CS4912 offers a cost effective solution for digital audio processing. The CS4912 device, combined with firmware kits which minimize development time for car and consumer audio applications, provides a strong price/performance incentive to transition from analog to digital audio signal processing in these markets.

Cirrus Logic

Cirrus Logic is a premier supplier of precision linear circuits and advanced mixed-signal system-level chip solutions, the latter which demand high-performance mixed-signal processing, embedded DSP, algorithms and firmware. The company's products, sold under its own name and the Crystal product brand, enable high-volume applications in mass storage, communications, consumer electronics and industrial markets. Additional information about Cirrus Logic is available at www.cirrus.com.

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Note to editors: Cirrus Logic is a registered trademark of Cirrus Logic Inc. All other product names noted herein may be trademarks of their respective holders.