VS1000 is a system-on-a-chip (SoC) Ogg Vorbis (license-free audio codec) player.
VS1000 contains a high-performance DSP core VSDSP4, NAND-FLASH interface, Full Speed USB port, general-purpose I/O pins, SPI interface, UART, as well as a high-quality variable-sample-rate stereo DAC, and an earphone amplifier with a common voltage buffer. VS1000 device also features internal voltage regulators and voltage monitor, so it can be powered from a single 3.7V to 5.25V voltage.
See more detailed information from VS1000 page.
See also a VS1000 Audio Module VS1000 Audio Module.