VS1002d is a single-chip MP3 audio decoder. It contains a high-performance, low-power DSP processor core VS DSP4, working data memory, 5
KiB instruction RAM and 2.5 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 variable-sample-rate mono
ADC and stereo DAC, followed by an earphone
amplifier and a ground buffer.
VS1002d 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, sigma-delta 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.