Introduction

The MAS 35x9F is a single-chip, low-power MPEG layer 2/3 and MPEG2-AAC audio stereo decoder. It also contains the G.729 Annex A speech compression and decompression technology for use in memorybased or broadcast applications. Additional functionality is achievable via download software (e.g., CELP voice decoder, Micronas SC4 (ADPCM) encoder/decoder).

Features

Firmware

– MPEG 1/2 layer 2 and layer 3 decoder

– Extension to MPEG 2 layer 3 for low sampling rates (“MPEG 2.5”)

– Extraction of MPEG Ancillary Data

– MPEG 2 AAC decoder (low-complexity profile)

– Micronas G.729 Annex A speech compression and decompression

– Master or slave clock operation

– Adaptive bit rates (bit rate switching)

– Intelligent power management (processor clock is dependent on sampling frequencies)

– SDMI-compliant security technology

– Stereo channel mixer

– Bass, treble, and loudness function

– Micronas Bass (MB)

– Automatic Volume Control (AVC)

Interfaces

– Two serial asynchronous interfaces for bit streams and uncompressed digital audio

– Parallel handshake bit stream input

– Serial audio output via I2S and related formats

– S/PDIF data input and output

– Controlling via I2C interface

Hardware Features

– Two independent embedded DC/DC converters, (e.g., for DSP and flash RAM supply)

– Low DC/DC converter start-up voltage (0.9 V)

– DC converter efficiency up to 95

– Battery voltage monitor

– Low supply voltage down to 2.2 V

– Low power dissipation, e.g., 87 mW (128kBit/s, 44.1 kHz, Headphone playback)

– High-performance RISC DSP core

– On-chip crystal oscillator

– Hardware power management and power-off functions

– Microphone amplifier

– Stereo A/D converter for FM/AM-radio and speech input

– CD quality stereo D/A converter

– Headphone amplifier

– Noise and power-optimized volume

– External clock or crystal frequency of 13...28 MHz

– Standby current