Features
 Mixes three audio sources
– General MIDI 1+ / SP-MIDI
– WAV (PCM + IMA ADPCM)
– Microphone or line input
 Encodes IMA ADPCM from microphone,
line input or mixed output
 Input streams can use different sample
rates
 EarSpeaker Spatial Processing
 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
VS1103b is a single-chip MIDI/ADPCM/WAV
audio decoder and ADPCM encoder that can
handle up to three simultaneous audio streams.
It can also act as a Midi synthesizer.
VS1103b contains VS_DSP4, a high-performance,
proprietary low-power DSP processor
core, 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, a UART,
as well as a high-quality variable-sample-rate
mono ADC and stereo DAC, followed by an
earphone amplifier and a common buffer.
VS1103b receives its input bitstreams through
serial input buses, which it listens to as a system
slave. The input streams are decoded
and passed through digital volume controls to
an 18-bit oversampling, multi-bit, sigma-delta
DAC. Decoding is controlled via a serial control
bus. In addition to basic decoding, it is
possible to add application specific features,
like DSP effects, to user RAM memory.