SLAU723A October 2017 – October 2018 MSP432E401Y , MSP432E411Y
The device has no control over the scheduling of transactions as scheduling is determined by the host controller. The USB controller can set up a transaction at any time. The USB controller waits for the request from the host controller and generates an interrupt when the transaction is complete or if it was terminated due to some error. If the host controller makes a request and the device controller is not ready, the USB controller sends a busy response (NAK) to all requests until it is ready.