VLSI Implementation for Portable Application Oriented MPEG-4 Audio Codec

In this paper, we present an audio codec for portable application, which supports MPEG-2/MPEG-4 AAC LC Profile. The presented codec has been implemented using UMC/HJTC 0.18um CMOS technology. In this implementation, optimized algorithms are developed and most memory and calculation units are shared between encoder and decoder so that the features of low power and low cost are achieved. The codec uses a total of 160k gates, 21KB RAM and 1.7KB ROM. Experiment shows that it is capable of real-time encoding/decoding AAC streams at only 5MHz working frequency. The codec's interface is simple so that it can be reused as IP macro and easily embedded into various multimedia systems.