Overview The LC78684E integrates, on a single chip, CD-ROM signal-processing functions, MP3 signal-processing functions, and CD-DA shockproof signal-processing functions. The LC78684E achieves significant power savings by implementing signal-processing functions using hardwired structures. A CD player that supports playback of MPEG audio (MP3) recorded on CD media as well as CD-DA shockproof playback can be implemented by combining this IC with a CD DSP, DRAM, and audio D/A converter, and other circuits. Features • MP3 Decoding Functions (MPEG audio standard [ISO/IEC 11172-3] layer 3) - Decodes to a digital audio signal MP3 data decoded by the CD-ROM decoder and outputs that audio signal. - Supports all bit rates, including variable bit rate operation. - Supports the following sampling rates. MPEG1 (Fs = 32 K, 44.1 K, 48 K) MPEG2 (Fs = 16 K, 22.05 K, 24 K) MPEG2.5 (Fs = 8 K, 11.025 K, 12 K) - Can read out the MPEG header and ancillary data. - Automatically mutes the signal on CRC errors using an MP3 CRC check function. - External MPEG serial data input function supports memory card playback. • CD-ROM Decoding Functions - Supports CD-ROM modes 1 and 2 (forms 1 and 2) - Faithfully reproduces data stored on CD-ROM discs using CD-ROM error correction functions. - Header and sector management - Supports playback speeds up to 4×. - In addition to data buffering also supports C2 error flag buffering. - Provides external serial output of decoded CD-ROM data. • CD-DA Playback Functions (Shockproof support) - Shockproof operation for about 180 seconds (compressed mode) when 64M DRAM is used. - Shockproof function supports compressed, uncompressed, and data through modes. - VCEC (variable speed) supports up to 4×-speed playback. • Audio Signal Processing - Serial audio signal output using LRCK, BCK, and DATA signals. (I²S format, either 16-bit or 20-bit precision PCM output, data-slot supports 16-bit, 24-bit, and 32-bit modes) - Digital bass boost function (4 modes), attenuator function, and muting (-f, -12 dB) - Provides a base clock (384 fs) output pin for use with external digital filters and D/A converters. • DRAM Interface - Supports the use of from 1M to 64M of external DRAM (EDO, 2CAS, 16-bit data bus memory) - Supports allocation of a user area in DRAM during CD-ROM (MP3) playback. • Package and Power Supply Voltage Specifications - Package: Sanyo QFP80 (14 × 14) (unit: mm) - Supply voltage Internal power supply: 1.8 V (typical) I/O power supply: 3.3 V (typical) Analog system power supply: 3.3 V (typical)
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