Question: Does the PSoC® family of devices support the USB Audio Class? If so, are there any example projects that can be used as a reference?
All PSoC 3 and PSoC 5LP devices that are USB capable support the USB Audio Class and conform to it as a slave device. Additionally, PSoC Creator™ supports the USB Audio Class by default. The potential applications for USB audio are quite large and at the moment, Cypress provides a limited number of example projects for reference. Two of the available example projects are included with PSoC Creator: USB_MIDI and USB_AUDIO. These projects can be obtained using the Find Example Project window, accessed via either the PSoC Creator Tool Bar (File > Example Project) or the PSoC Creator Start Page. Figure 1 shows the available USB audio projects that can be found using the USBFS keyword.
Figure 1. Find Example Project Window
Additionally, PSoC 4 Pioneer Kit Community Project#102 – USB Audio using the PSoC 5LP is a more advanced example project that can be found at the Element14 community forum, developed by Cypress, and is targeted towards PSoC 5LP devices. This project builds upon the basics by including information on using an I2S interface and a pulse density modulation (PDM) microphone.
These three examples should provide the fundamental framework needed to develop a broad range of audio applications using isochronous (ISO) endpoints. In conjunction with these examples, you can use information provided in the Universal Serial Bus Device Class Definition for Audio Devices, provided by the USB Implementers Forum (USB-IF), to develop additional audio applications.
Note that Microsoft® Windows® 2000/XP and beyond are released with built in Audio Class Drivers. No additional drivers need to be provided by the end user. For additional information on USB descriptors and ISO endpoints, refer to the following application notes or contact Cypress Technical Support.