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
â MPEG 1/2 layer 2 and layer 3 decoder
â Extension to MPEG 2 layer 3 for low sampling rates (âMPEG 2.5â)
â Extraction of MPEG Ancillary Data
â MPEG 2 AAC decoder (low-complexity profile)
â Micronas G.729 Annex A speech compression and decompression
â Master or slave clock operation
â Adaptive bit rates (bit rate switching)
â Intelligent power management (processor clock is dependent on sampling frequencies)
â SDMI-compliant security technology
â Stereo channel mixer
â Bass, treble, and loudness function
â Micronas Bass (MB)
â Automatic Volume Control (AVC)
Interfaces
â Two serial asynchronous interfaces for bit streams and uncompressed digital audio
â Parallel handshake bit stream input
â Serial audio output via I2S and related formats
â S/PDIF data input and output
â Controlling via I2C interface
Hardware Features
â Two independent embedded DC/DC converters, (e.g., for DSP and flash RAM supply)
â Low DC/DC converter start-up voltage (0.9 V)
â DC converter efficiency up to 95%
â Battery voltage monitor
â Low supply voltage down to 2.2 V
â Low power dissipation, e.g., 87 mW (128kBit/s, 44.1 kHz, Headphone playback)
â High-performance RISC DSP core
â On-chip crystal oscillator
â Hardware power management and power-off functions
â Microphone amplifier
â Stereo A/D converter for FM/AM-radio and speech input
â CD quality stereo D/A converter
â Headphone amplifier
â Noise and power-optimized volume
â External clock or crystal frequency of 13...28 MHz
â Standby current < 10 µA
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