USB Audio 2.0 Reference Design


  • XMOS USB Audio solutions utilise High Speed USB 2.0 with 480Mb/s of audio data, delivering 24-bit audio, sample frequencies up to 192kHz and from 2 to 40 audio channels. The highly flexible XMOS devices allow you to taylor your solution to the exact mix of interfaces and digital processes for your product.
  • This USB Audio solution utilises the XS1-L1 device to provide high quality digital audio connectivity for pro-audio and consumer applications. The design provides certified USB 2.0 High Speed device and Audio Class 2.0 device class implementations with configurable digital audio interfaces, peripherals and the ability to integrate audio processing. The framework also includes support for USB Audio Class 1.0.



  • Complete reference design
  • Stereo audio input via I2S
  • Stereo audio output via I2S
  • Optical digital audio output (S/PDIF)
  • Bit perfect digital audio data, 24-bit @ 192kHz
  • The industry's lowest round-trip audio latency
  • Supports standard sample rates - 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz**, 192kHz
  • USB bus-powered. No external power supply required
  • Low jitter audio master clocks using asynchronous USB synchronization
  • Built on the 500 MIPS, 8 threads, XS1-L1 processor
  • XMOS XSYS debug header for easy programming/debug from the host using the XMOS XTAG2 debug adapter
  • **176.4kHz SPDIF not supported on L1 USB Audio board. 176.4KHz SPDIF requires use of 22.5972MHz crystal instead of 11.2896MHz


Driver Support

  • XMOS USB Audio Class 2.0 is supported by Apple OSX version 10.6.4 and above - no driver install required. Support for Windows is provided via XMOS partners, Thesycon, CEntrance and Ploytec. The drivers are configurable and provide support for WDM/Direct X and ASIO 2.1.
  • An evaluation Thesycon Windows driver is supplied for use with reference designs. The Thesycon production driver is available through XMOS as a separate part number which bundles the driver with the XS1-L devices*, not requiring any upfront NRE fees, or through Thesycon directly using a customer negotiated payment model.
  • An evaluation Windows driver is available from the CEntrance or Ploytec, and production drivers are available directly from CEntrance and Ploytec.
  • Developers who want to customize the Windows drivers must provide their own USB VendorID/ProductID and Verisign Authenticode Certificate. See Configuring Windows Drivers for USB Audio for details.
  • * Access to the Thesycon production driver via the bundled part (XS1-L01A-TQ128-C5-THS/XS1-L01A-LQ64-C5-THS/XS1-L01A-TQ48-C5-THS) is subject to a minimum order quantity.



USB Audio 2.0 Reference Design Product Brief
USB Audio Software Design Guide
Adding DSP to the USB Audio 2.0 Reference Design