GENERAL DESCRIPTION This document describes how to implement an all-digital voice recorder using the MX93521 chip. The MX93521 is a Digital Recorder Data Pump which is controlled by an external microprocessor to perform various recorder function. The MX93521 is fully controlled by a HOST controller through a simple HOST interface protocol. The HOST could initiate many digital recording functions such as record, play, repeat, search, skip, insertion, message managing and self-diagnosis. Also, HOST could set MX93521 in VOCODER mode and use MX93521 as a speech compression/decompression data pump. The functions supported by MX93521 are listed as followed. FEATURES • Excellent sound quality by adopting 4800bps CELP speech compression alogorithm. • Silent Compression algorithm to further compress silence between speech. • Flash Memory Management alogorithm to manage down-graded Flash Memory to store compressed speech data. With silent compression, one 4Mbit flash memory could store up to 18 minutes speech. • Support 4/8/16/32 Mbit Samsung Flash Memory or its compatible parts • Support both parallel and serial microprocessor interface. • Codec Interface circuit (support both TP3054 and MX93000) • Host controllable LCD Module Interface • Host writable message header (4 bytes) for identification or index purpose • Powerful Editing Function • Varieties of operating function including Rewind, Fast Forward, Repeat and message editing etc. • Voice activated recording • Use Flash memory to store user data (data bank) • Upload/Download speech message data from/toHOST • VOCODER mode (VOice COmpressor/DEcompressoR) • Direct CODEC Play Mode (Play PCM/u-Law data received from HOST) • Play Voice Prompt from ROM/FLASH memory • DTMF tone genarator
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