DMA of USB Multiple Channel Audio | Cypress Semiconductor
DMA of USB Multiple Channel Audio
Using the demo CY8CKIT_046_USB_Audio as an example, I am trying to create a 4 channel USB audio adapter.
USBFS and I2S components both support the extra channels, but the data for 4 channels is interleaved in a frame according to http://www.usb.org/developers/docs/devclass_docs/frmts10.pdf Section 2.2.3
How the audio stream data is formatted to and from USBFS is not well documented but I am assuming it is still interleaved. So for example, each frame would be 6 bytes to I2S0, and then 6 bytes to I2S1.
Since the data has to go to different I2S FIFO registers I2S_RX_CHn_F0_PTR, it is unclear how to use DMA to accomplish it. Ideas?