Techniques for transmitted data through a USB port using a PCIe protocol are described herein. In one example, an apparatus includes a host controller, a root port, a multiplexor coupled to the host controller and the root port and a power delivery module. The power delivery module and the multiplexor can transmit and receive a request via a multimode input/output (I/O) interface and the power delivery module can detect a presence of an external device in response to the external device being coupled to the multimode I/O interface. The power delivery module can also send a first request to the external device to discover a vendor identifier of the external device, send a second request to discover at least one alternate mode supported by the external device, and send a third request to enable data transfer via the protocol.