The two MIPS R4000 CPUs will provide a platform for the digital contents of all audio, video and games in the mobile device, dubbed by Sony "the 'Walkman' of the 21st century" and scheduled for release late next year.

The Playstation portable, known formally as the PSP, was announced in May at the Electronic Entertainment Exposition in Las Vegas but details were not disclosed until last week.

Ken Kutaragi, president and chief executive officer of Sony Computer Entertainment Inc., told the Playstation Meeting 2003 here that PSP will have an LCD about 4.5 inches wide, with 480 x 272-dot resolution; a 60-mm-diameter disk system; and a proprietary Sony system called Universal Media Disc (UMD), all powered by the PSP engine.

That engine will be a single-chip solution built in the 90-nanometer process, with embedded DRAM, Vector floating engine, reconfigurable DSP engine, 3-D graphics engine, AVC (H.264) decoder, AES crypto system and interfaces. After PSP was announced in May, 802.11 Wireless LAN was added as standard equipment because "software creators strongly requested the function," said Kutaragi.

One of the 32-bit MIPS processors will be the PSP's main CPU for games while the other will be the media engine, handling signal processing of digital audio and video contents.

The two processors operate in the range of 1 MHz to 333 MHz at 1.2 volts. Each CPU uses embedded DRAMs. The main processor uses 8 Mbytes and the media engine uses 2 Mbytes.

Sony plans to make PSP a portable platform for a range of digital entertainment that goes beyond games.

For game performance, the rendering engine with embedded 2-Mbyte DRAM has a maximum processing speed of 33 million polygons/second. In addition to conventional triangle-based polygons,

the engine handles a curved-surface modeling called "nonuniform rational B-splines." The main CPU has a 3-D-CG extended instruction set.

The media engine handles audio and video processing, not game operation, so game title creators cannot directly program it. SCEI will provide basic program sets for these audio and video operations.

Advanced Video Coding (H.264), which the Joint Video Team is working to standardize, was adopted as the video coding format for PSP. AVC was developed to improve video compression efficiency for applications in which bandwidth or storage capacity is limited.

The 6-centimeter-diameter UMD system, which has a 1.8-Gbyte capacity using a red laser and two-layered-disk structure, can store the equivalent of about two hours of video content that's of the same quality as DVD images.

It uses the AVC Baseline profile at a transfer rate of 2 Mbits/s. When using the main profile at 1 Mbit/s, the disk can store about four hours of video content. "This will bring a new form of video sales," said Kutaragi. For audio decoding, the reconfigurable DSP handles such formats as ATRAC3 plus, AAC and MP3.

Sony and SCEI announced in May a marketing plan of two Playstation-related products, PSX and PSP. PSX targets a home video station with Playstation2 functions while PSP targets a mobile station with potable-game functions. Those two products will be based on Sony's silicon strategy, which makes full use of the 90-nm process jointly developed by Toshiba Corp. and Sony.

SCEI plans to show a PSP prototype at next year's Electronic Entertainment Exposition, to demonstrate game titles at the Tokyo Game Show in September 2004 and to introduce it worldwide in the fourth quarter.

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