VS1005 – All-In-One MP3 Audio System-on-a-Chip

Block diagram


The VS1005 product family is VLSI Solution's new flagship and first MP3 system-on-a-chip.

The features of VS1005 are particularly suited for portable audio devices, docking stations, and record-playback applications. It can be tailored for a specific application.

The Full Speed USB host function is useful in systems that require audio playback capability from external media such as USB memory sticks or drives, opening up many new applications in AV receivers and radio players. USB device mode is also supported.

The Ethernet interface provides Internet streaming capability over wired lines. I2S extends digital connectivity with other ICs. The RTC and battery backed registers provide alarm functions as well as very low power - low speed modes for the DSP.

The VS1005 SoC takes a new approach in application development when compared to VLSI's earlier products. The multitasking operating system VSOS and the object code library MegaLib offer services that can be utilized with VLSI Solution's Integrated Development Environment VSIDE. This combination makes writing applications to VS1005's 256 KiB RAM memory a straightforward and intuitive process. To further extend VS1005's usability, code can be loaded dynamically from any non-volatile memory, including VS1005's optional internal 1024 KiB flash memory. The internal flash memory can be protected, making it possible for developers and third parties to protect their code.

The MegaLib library includes all VLSI Solution's existing codecs: MP3 and Ogg Vorbis encoders, MP2, MP3, WMA, OGG, AAC LC, FLAC, IMA and WAV PCM decoders, and other functions: FM including RDS, file I/O, device drivers, application loading, multitasking, graphical interface functions, audio processing, etc.



  • Single power input
  • Internal voltage regulators
  • 5-input multiplexed SAR for monitoring
  • Optional battery for RTC and backup registers

Analog Audio

  • 2 x 24-bit / 96kHz DAC
  • 3 x 24-bit / 192kHz ADC
  • Integrated FM tuner with RDS, Japanese band included (76-108 MHz)
  • Stereo headphone output
  • Stereo microphone amplifier

Digital Audio

  • S/PDIF input and output (+AES/EBU support)
  • I2S input and output
  • 24-bit sample rate converter
  • Full Speed USB audio device
  • Ethernet interface


  • SD card interface
  • Optional embedded flash
  • NAND flash interface
  • Internal SRAM (256 KiB) and ROM (256 KiB)

General Purpose I/O

  • Full Speed USB host / device
  • PWM output
  • UART
  • 2 SPI buses, host and slave mode supported
  • Resistive Touch Screen interface
  • JTAG interface for hardware debug
  • 8-bit bus for LCD

Other Hardware Features

  • Operates with a single clock
  • Optional real-time clock
  • Embedded flash memory can be copy protected
  • Power button pin, software-controlled power-off

VSOS Firmware Highlights

  • Programs are written using VLSI Solution's Integrated Development Environment VSIDE
  • Decoders: MP3, WMA, Ogg Vorbis, AAC LC, FLAC, ALAC, DSD, RIFF WAV
  • Encoders: MP3, Ogg Vorbis
  • DSP audio features: EarSpeaker, Parametric EQ, VU Meter, Mixer, Speed Shifter, Pitch Shifter, etc
  • File I/O for SD cards and NAND flash.
  • FM tuner and RDS decoder
  • USB host and slave libraries
  • VSOS Shell Environment for easy prototyping and software development
  • Graphical display with resistive touch control

Audio Format Support

Audio Decoder Format Support

Audio Decoder Format "Up To" Support Table

Audio Format

From SD Card

From USB Stick

ALAC (Apple Lossless)

96 kHz 24-bit

48 kHz 24-bit

FLAC (Free Lossless Audio Codec)

96 kHz 24-bit

96 kHz 24-bit

AIFF (Apple PCM)

352 kHz 32-bit

96 kHz 24-bit

RIFF WAV (Microsoft PCM)

352 kHz 32-bit

96 kHz 24-bit

Ogg Vorbis

96 kHz 1000 kbit/s

96 kHz 500 kbit/s

MP3 (Not VS8005)

48 kHz 320 kbit/s

48 kHz 320 kbit/s

AAC-LC (Advanced Audio Codec)

48 kHz 280 kbit/s

48 kHz 280 kbit/s

WMA (Windows Media Audio)

48 kHz

48 kHz

DSD64 / 128 / 256

DSD256 11.3 MHz


Audio Encoder Format "Up To" Support Table, No External Memory

Audio Format

To SD Card

To USB Stick

MP3 (VS1205 Only)

48 kHz 320 kbit/s

48 kHz

Ogg Vorbis

48 kHz

24 kHz



Product variations

Device ID MP3 Encoder MP3 Decoder Embedded 8Mbit Flash
VS1005G-Q   X  
VS1005G-F-Q   X X
VS1205G-Q X X  
VS1205G-F-Q X X X


QFN88 10x10x0.8mm