The USB11PHY is an IP version of USB transceiver. It receives data with DP and DM and transfers data to USB11 core with RCV, VM and VP. It is designed in standard logic to interface with the physical layer of Universal Serial Bus. It is capable of transmitting and receiving serial data at either full speed (12M bit/s) or low speed (1.5M bit/s) data rates. The serial interface engine (SIE) controls the state of USB11PHY through the OEN signal. When in receiving mode, it receives data on the output RCV, VM and VP of USB11PHY; when in transmitting mode, it drives the input VPO and VMO of USB11PHY.