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    • Simplified Version of PHYSICAL LAYER SPEC
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About the SD Memory Card

Concept of SD Memory Card

The SD Memory Card is a groundbreaking new bridge media that's helping to pave the way for tomorrow's fully networked society. This tiny, easy-to-use card offers a host of powerful advantages. It links various kinds of digital equipment through its easy connectivity, that supports a host of application formats and does not require the use of a PC. Further, the SD Memory card has the broad interoperability and compatibility needed to ensure that its applications will continue to expand far into the future. Already supported by more than 665* companies around the world, the SD Memory Card is well on its way to becoming the de facto standard memory card for digital connectivity. Soon, the SD Memory Card will provide universal access to an even wider array of multi-media data. The ubiquitous network era is coming, and its key is the SD Memory Card.
*As of December 31, 2003

Simplified Version of PHYSICAL LAYER SPEC

The SD Memory Card measures a mere 24mm by 32mm by 2.1mm. Its slim, compact design promotes easy handling, an important factor for a "bridge media" which you can move between different appliances. Using decoder software, an SD Memory Card-compatible device can play music, video clips and more without a drive mechanism like those in CD and DVD players. This allows the equipment to be more compact and gives product designers new creative freedom. Reliability is also improved through the elimination of skipping on music files. The miniSD™ Card, measuring 20 x 21.5 x 1.4mm (W x L x T), is also available as smaller factor of the SD Memory Card.

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Small size is not enough. Capacity is equally important. SD Memory Cards are currently available in several capacities, and new 2, 4 and 8GB cards are on the way. This kind of large capacity is essential for use with a variety of digital content types, and especially with high-quality video.

Increasing data volumes and the increasing range of digital content has created demand for memory cards with higher data transfer rates.

Content Protection for Recordable Media (CPRM), the content protection technology used for the SD Memory Card, is key to enabling a new distribution system for music and other commercial media, because it assures a high level of protection against illegal copying. The technology was developed by 4C (The digital contents copyright protection technology licensing organization of IBM, Intel, Matsushita, and Toshiba.)

Having a proven record in DVD, this protection is enhanced in the SD Memory Card through the use of "key revocation" technology that is built into the card.

The card's control circuitry allows data to be read and written (in its protection area) only when appropriate external devices are detected. A check-out (copying) from a PC to the SD Memory Card is restricted to 3 copies in compliance with the SDMI specification. All SD-Audio products comply with SDMI.

The SD Memory Card copyright protection function has the following features:

• Access to the SD Memory Card must be enabled by authentication between devices
• A random number is generated each time there is mutual authentication and exchange of security information

With SDIO cards, new functions such as Digital TV Tuner, wireless LAN 802.11b, FM Radio etc. are added to host devices equipped with SD card slots.

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