Electronic Design

Mobile Jukebox Engine Jazzes Up Digital Audio, JPEGs

One chip encodes/decodes digital audio files as well as decodes JPEGs for a total entertainment solution.

Handheld digital music jukeboxes storing thousands of songs have quickly created a burgeoning market segment. But simple audio capture and playback leaves little room for differentiation. Now, a second-generation solution from PortalPlayer adds image playback and TV display capabilities to the mobile jukebox.

The PP5020, a complete digital media subsystem on one chip, trims the bill of materials. With minimal external logic, it can encode analog audio into digital audio and then play it back. It also can decode JPEG image files and play them back on a local LCD display or on a TV receiver that connects to the PP5020 through a third-party NTSC/PAL TV encoder chip (see the figure). And, the chip can encode MP3 and ACELP.NET audio formats and decode MP3, WMA, AAC, and ACELP.NET formats. For images, it decodes both JPEG and motion JPEG files.

A pair of on-chip ARM7TDMI RISC processors handles housekeeping and audio and image processing. Each CPU operates at 80 MHz, and the two link together through a crossbar switch that achieves zero-wait-state accesses to the 96 kbytes of internal SRAM. A unified cache of 8 kbytes also is part of each CPU. Other resources include a six-channel DMA controller, a memory controller that supports two banks of SDRAM (up to 128 Mbytes/bank) on a 16-bit bus, and two banks of NOR flash (also up to 128 Mbytes/bank) on an 8- or 16-bit bus.

An ATA-66 hard-disk controller supports up to four storage devices (CD-ROMs, CR-R/W, hard disks, and/or IBM Microdrives), and a USB 2.0 high-speed serial link provides On-the-Go support. A FireWire (IEEE-1394a) controller (external physical-layer interface required) offers an alternative to USB 2.0 and can link the jukebox to digital video cameras and set-top boxes.

The PP5020's LCD controller can drive single-scan 1-, 2-, or 4-bit monochrome STN LCD panels. Its digital TV controller will support TFT panels of up to 640-by-480 pixel resolution with 18-bit 5:6:5 RGB data and a 60-Hz refresh rate. The chip connects to a TV set via a CCIR601/656 TV output, which delivers a signal to an external NTSC/PAL encoder. It also packs a direct interface to an I2S stereo audio codec and a direct interface to a Sony/Philips digital interface for digital audio input or output.

An available 5-by-8 switch matrix controls keypads with up to 40 buttons. An additional 13 general-purpose I/O lines handle player navigation controls. Four optosensor inputs enable next-generation multidimension human-interface controllers to link to the chip. Four pulse-width-modulated outputs for contrast and brightness control help with the display. Extensive power-management features permit the chip to deliver more than 15 hours of playback from a single AA alkaline battery.

A full suite of development support tools are part of the Digital Media Firmware Developer's Kit. The tools and library modules (codecs, database engines, and other functions) allow developers to rapidly create differentiated platforms. To support the image viewing and setup, companies can bundle PortalPlayer's image-management software package with the finished system. With the software, users can set up a slideshow, perform some photo editing, and back up data by burning slideshows, photos, and music to CDs.

Housed in a 240-contact thin fine-pitch BGA package, the PP5020 operates from a 3.3-V supply (1.8-V core voltage). In large quantities, it will cost less than $20 each. Samples are available from stock.

PortalPlayer Inc.
www.portalplayer.com;
(408) 521-7000

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