The following documents describe in detail our 8051-based MP3 Player, a new generation digital audio player. It uses the widely available ISO/IEC MPEG Audio Layer 3 (MP3) compression standard. The Player is designed to work as a portable system that can be carried around and operated using a standard 9 V AA battery. I was keen to do this project because of my previous interest in the MPEG audio compression standards, as well as a general liking for projects involving equal work on hardware and software. I guess this one just fit the role perfectly!

The MP3 format has recently caught attention worldwide because of its superior compression algorithm, reducing file sizes by as much as 10 times with a minimum perceptible reduction in sound quality. These days, cheap and efficient codecs are widely available that convert the MP3 format to simple PCM digital format that can be easily converted to an analog signal for playback. With the advent of Flash™ memory, portable and reliable data storage has become a reality. I have exploited these two technologies to my advantage.

The following are a few terms that you will encounter frequently in this document:

• MPEG - Motion Picture Experts Group

• MP3 - MPEG I Audio Layer III

• PCM - Pulse Code Modulation

• FCC - Federal Communications Commission

• ISO - International Organization for Standardization

• IEC - International Electro-technical Commission

The next page contains a background on the MP3 format, so don't lose hope if you're wondering what all the hype is about!