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 < 10 µA