Casio Computer and Oki Electric Industry Jointly Develop Sound-Reproduction LSI for Mobile Phones

- First PCM sound LSI produces remarkably natural sound -

Oki Electric will start sample shipments of the ML2857 in August and begin full-scale sale of the product. Shipments are projected to reach five million units in fiscal 2000 and 20 million units by fiscal 2002.

As mobile phones continue to grow in popularity, an increasing number of users are downloading music to create personalized ringing melodies for their phones. Playback capabilities have continued to improve to the point where some models already on the market can play polyphonic sounds.

By storing digitized natural sound and then converting it back into analog sound signals for playback, the ML2857 generates sound quality that is much more natural than synthesized digital sound. It can reproduce some 100 different timbres over a range of five octaves, including up to 12 polyphonic sounds and five timbres simultaneously. "The PCM sound generated through the ML2857 will surely alter public perceptions of current ringing melodies," said Dr. Masayoshi Ino, managing director of Oki Electric.

The chip is ideally suited for use in small, lightweight mobile phones. The single-chip design measures just 6.3 x 6.3 mm (minimum size) and its low-power design requires only three volts to run. Moreover, its built-in sequencer decreases load on the mobile phone's system microcontroller.

The ML2857 also creates sound directionality, which helps users to better recognize when their own phone is ringing, particularly in crowds.

"Mobile phones equipped with our new LSI have ringing melodies that come alive and are truly enjoyable to listen to," explained Casio Managing Director Masayuki Hakata.

Casio, which introduced the first Casiotone musical keyboard in 1980, has substantial expertise in the field of sound LSIs, including sampling technology for reproducing natural sounds and digital signal processing technology. Oki Electric is a leading developer of LSIs for mobile devices and components for a wide array of devices. The company commands 80% of the domestic market and 35% of the overseas market for voice synthesis and record/playback LSIs.

The core intellectual property and sound data format were developed by Casio, drawing off of its extensive technology for electronic instruments. Oki Electric handled design and is responsible for manufacturing and sales. Both companies will promote the product.

IEP Technologies, a joint-venture company that the two firms set up last November, will use the ML2857 in wafer-level chip-size packages (CSPs) that it will develop and produce for extra-high-precision mounting in compact, high-performance devices.

Oki Electric and Casio are planning to adapt their new LSI to the general MIDI (GM) format, the de facto standard for music reproduction data. This added feature will enable mobile phones to accept increasingly complex music, which should stimulate increase supply of music for mobile phones via the Internet and even through kiosks. In addition, expanded uses for mobile phones, such as viewing the web while listening to background music, will create opportunities for periphery business. The two companies also intend to develop ML2857 applications in other devices, such as buzzers and alarms that reproduce high-quality sound and music.

About Casio
CASIO COMPUTER CO., LTD. is one of the leading consumer electronics companies in the world. Since its establishment in 1957, CASIO has been active in the development of electronic calculators, timepieces, musical instruments, LCD TVs, mobile information devices, and electronic devices. Visit Casio's global web site at http://www.casio.co.jp/

About Oki
Founded more than a century ago in 1881, Oki Electric Industry Co., Ltd. is Japan's first telecommunications manufacturer headquartered in Tokyo, Japan. With more than 20,000 employees worldwide, Oki Electric provides customers with top-notch products and technologies for telecommunication systems, information systems and electronic devices through its corporate slogan "Oki, Network Solutions for a Global Society." Oki's all manufacturing facilities are ISO9001 and ISO14001 certified.

Explanation of terms used in this release

• PCM (pulse code modulation):

  This sound source format converts analog sound into continuous digital pulses that are stored in memory, and then converted back into analog sound signals for playback. Compared with digital sounds synthesized in sine waves, rectangular waves and other signals, the PCM format enables natural sound, such as that of instruments, to be reproduced faithfully.

• IP (intellectual property):

  IP refers to the treatment of electronic circuit functions as assets. Developed technologies can be reused, if accumulated as IP. In today's semiconductor industry, in which high-performance chips must be quickly developed, circuit design based on IP is a necessity.

• Wafer-level CSP (chip-size packaging):

  Conventionally, CSPs are assembled individually from LSI chips cut out of wafers. Wafer-level CSPs, however, are packages that are cut into chip sizes after copper rewiring, electrode terminals creation and resin sealing are performed on the entire wafer. The process enables packages to be shrunk down to the exact dimensions of chips and helps to reduce costs.

• GM (general MIDI):

  The GM standard allows electronic instruments to exchange music reproduction data. Tones are assigned standardized numbers for playback in nearly identical fashion by different systems. Nearly all devices and music data used for karaoke systems are based on the GM standard. Sound LSIs made compatible with this standard could be used for a vast range of content.