Features
 Decodes MPEG 1 & 2 audio layer III
(CBR +VBR +ABR); WMA 4.0/4.1/7/8/9
all profiles (5-384kbit/s); WAV (PCM +
IMA ADPCM); General MIDI / SP-MIDI
files
 Encodes IMA ADPCM from microphone
or line input
 Streaming support for MP3 and WAV
 Bass and treble controls
 Operates with a single 12..13 MHz clock
 Internal PLL clock multiplier
 Low-power operation
 High-quality on-chip stereo DAC with no
phase error between channels
 Stereo earphone driver capable of driving
a 30
load
 Separate operating voltages for analog,
digital and I/O
 5.5 KiB On-chip RAM for user code /
data
 Serial control and data interfaces
 Can be used as a slave co-processor
 SPI flash boot for special applications
 UART for debugging purposes
 New functions may be added with software
and 4 GPIO pins

Description
VS1003 is a single-chip MP3/WMA/MIDI audio
decoder and ADPCM encoder. It contains
a high-performance, proprietary low-power DSP
processor core VS_DSP4, working data memory,
5 KiB instruction RAM and 0.5 KiB data
RAM for user applications, serial control and
input data interfaces, 4 general purpose I/O
pins, an UART, as well as a high-quality variablesample-
rate mono ADC and stereo DAC, followed
by an earphone amplifier and a common
buffer.
VS1003 receives its input bitstream through
a serial input bus, which it listens to as a
system slave. The input stream is decoded
and passed through a digital volume control
to an 18-bit oversampling, multi-bit, sigmadelta
DAC. The decoding is controlled via a
serial control bus. In addition to the basic decoding,
it is possible to add application specific
features, like DSP effects, to the user
RAM memory.