Cirrus Logic's Dolby Digital Multi-Channel Audio Decoder Receives Full Certification From Dolby Laboratories; New Crystal DSP Chip Solution Targets High-Performance Consumer Audio Applications.

AUSTIN, Texas--(BUSINESS WIRE)--July 22, 1997--The Crystal Semiconductor Products Division of Cirrus Logic Inc. (NASDAQ:CRUS) today announced that the CS4923 Dolby(R) Digital and Dolby Surround Pro Logic(TM) audio decoder has received full certification by Dolby Laboratories Inc.

Designed for emerging DVD, Home Theater and Set-Top entertainment applications, the CS4923 provides audio performance commonly found only in multi-chip solutions. In addition, the highly-integrated Dolby Digital Decoder provides the capacity for all of Dolby Laboratories' post decode system requirements in a single, consumer-electronic-friendly, 44-pin PLCC package.

Consumer Support for Dolby Digital

"The marketplace acceptance of Dolby Digital technology has been very gratifying for us. It appears that this technology has become a common digital media standard, guaranteeing portability across consumer audio, professional audio, broadcast audio and the personal computer," explained Charles Seagrave, general manager, Digital Technologies, Dolby Laboratories Licensing Corporation.

"We are happy to have Crystal Semiconductor, a well-known brand of professional and consumer audio, deliver a highly-integrated Dolby Digital playback solution to these markets. The CS4923 implements all of our audio decoding requirements as well as our system feature requirements on a single chip."

The CS4923 Dolby Digital multi-channel audio decoder can be teamed with the Crystal CS4226 multi-channel audio codec to fulfill the entire digital signal processing and data conversion requirements for all product classifications and groups of Dolby Digital Systems.

"We see the CS4923 as the most complete answer for high-end audio," said Peter Madnick, president of DTG Inc., the designers of the SOUNDSTREAM Technologies' forthcoming MOSAIC home A/V system controller.

"The CS4923 and CS4226, as a DSP and data converter chipset, are a perfect system solution for Dolby Digital, Dolby Surround Pro Logic and specialized custom post processing. Crystal Semiconductor has provided for all of today's requirements along with a pin-compatible future roadmap tailored for all flavors of DVD audio."

The introduction of the CS4923 is part of a broader strategy by Cirrus Logic, Inc. to leverage its expertise in the professional audio and PC multimedia marketplace and apply it more broadly to the consumer electronics industry.

Commenting on today's announcement, Terry Ritchie, director of marketing for the Crystal Semiconductor line of Consumer & Professional Audio DSP Products, explained, "The CS4923 can support the entire spectrum of Dolby Digital opportunities, from very high-end audiophile home theater equipment to home A/V receivers, HDTV sets, DVD players, DBS set-top boxes, and multimedia PC add-in cards.

"We are anticipating wide adoption of the CS4923 decoder and CS4226 codec, given their high-quality output, ease of use, overall system implementation and pin-compatible roadmap for alternative DVD audio standards."

Eric Broockman, vice president and general manager of Cirrus Logic's Crystal Semiconductor Products Division, added, "In addition to traditional home audio products, Dolby Digital is also making its appearance in set-top boxes and will soon appear in HDTV. In many current DBS set-top boxes, we have been very successful with MPEG stereo audio decoders. The CS4923 decoder is an outgrowth of this 24-bit technology.

"With the CS4923 we now provide a path for realizing high-end set-tops by offering Dolby Digital and Dolby Surround Pro Logic along with custom DSP audio capabilities like virtual 3D enhancement, graphic equalization, reverberation and concert hall effects. The result is an auxiliary 5.1 channel decoder for premium movie channels, plus DVD audio compatibility and audio controller functionality for value-added audio special effects.

"Consumers have demonstrated they will spend more for audio enhancements and the CS4923 yields a low-cost feature set for higher tier set-top boxes. We have listened to our customers and have delivered a product with superior performance and ultimate flexibility, which our customers have come to expect from the Crystal brand."

System Features

The primary strengths of the CS4923 are: abundant digital signal processing capacity, on-chip RAM based program memory, large data memory for input buffer and delay buffer, and a complete armament of flexible audio peripheral interfaces.

-- Processing capacity -- The CS4923 provides approximately 50 MIPS of 24-bit DSP when using the internal phase-locked loop. An external clock mode can be utilized to deliver more MIPS for higher performance requirements.

Simultaneously, two channels of compressed and/or PCM data are directly pipe-lined to a large two-channel input buffer to save the DSP the overhead of moving input data.

-- On-chip RAM -- The dual-channel input buffer facilitates implementation of a thorough set of robust error concealment strategies. The input buffer can accept smooth delivery or very-high-speed burst delivery from transport demultiplexors. The two-channel input buffer also makes it easier to transition between bitstream and linear PCM input, thereby avoiding audible anomalies.

-- Input and Delay Buffering -- To preserve DSP MIPS, hardware acceleration is achieved with a dedicated barrel shifter that is directly connected to the input buffer. The barrel shifter and DSP provide a soft solution for parsing and decoding any compressed data layer and/or linear PCM delivered from two of the following: IEC958 input, a pair of I2S or non-I2S 96Khz capable multi-channel serial inputs, a dedicated burst serial input or a byte-wide interface.

-- Flexible audio peripheral interfaces -- For output, the CS4923 is also fully programmable, providing multiple modes that support all industry-standard serial interfaces. The output timing can be master or slave and is capable of 96kHz operation. In addition to the serial digital outputs, the CS4923 is equipped with an IEC-958 transmitter port for delivery of the audio bitstream or linear PCM. A clock manager is provided to generate the DSP clock and the over- sampled timing for external D/A & A/D converters. Overall, the CS4923 can be initialized and controlled from a standard serial or parallel interface, or optionally booted from an external memory.

In addition to 5.1 channels of audio decoding, the CS4923 also provides a Dolby Surround Pro Logic Decoder, a pink noise generator, variable cross-over filters and the bass steering manager, which are system requirements for Dolby Laboratories' Dolby Digital multi-channel products.

The device is also capable of performing further customized digital signal processing with its reserve MIPS and extra program and data RAM. Manufactured using a 0.35 micron CMOS process, the CS4923 is fabricated at Cirrus Logic's MiCRUS facility in East Fishkill, New York.

Pricing and Availability

The CS4923 is available in a 44-pin PLCC and will sell for under $15 per unit in quantities of 10,000. Samples of the CS4923 are available now.

Crystal Semiconductor Products Division

The Crystal Semiconductor Products Division of Cirrus Logic designs, manufactures, and markets advanced analog and digital integrated circuits for data acquisition, consumer/professional audio and video and imaging applications.

The Crystal brand is recognized for providing high-performance mixed-signal and DSP solutions for consumer and industrial markets.

Cirrus Logic Inc.

Cirrus Logic is a leading manufacturer of advanced integrated circuits for personal computing, communications, mass storage, consumer and industrial markets. The company's "systems in silicon" add high value and software richness to major brands worldwide.

With a focus on creating innovative microperipheral chip solutions that make the electronic products more natural and exciting to use, Cirrus Logic is committed to technology leadership in the Interactive Age.

Cirrus Logic news releases may be obtained by fax by dialing 800/359-6414, or by dialing 510/249-4200 from outside the United States, or via the Internet on the world wide web at http://www.cirrus.com/ . -0-

Note to editors: "Dolby" and "Pro Logic" are trademarks of Dolby Laboratories. All other trademarks are the property of their respective holders.

CONTACT: Cirrus Logic, Inc.

Terry Ritchie, 512/912-3733

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Jo-Dee Benson, 512/912-3823

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