Figure 2-3 explains the architecture of the USB offering on AM261x devices. The MCU_PLUS_SDK v10.00 has the DFU and CDC applications available out-of-box that use the underlying TinyUSB stack classes. The USB applications and classes are supported over both FreeRTOS™ and NoRTOS and the TinyUSB porting layer and device driver layers are OS agnostic, meaning the user gets freedom to choose between NoRTOS and FreeRTOS, then choose the USB class from the stack and build a USB application seamlessly.

The USB DCD layer has APIs defined to open, close, configure endpoints, initialize the device class driver and the USB driver, configure interrupts, enable or disable interrupts. The DCD layer also has input and output completion call back functions along with functions to submit a transfer request and general debug logging functionality.