Systems and method for operating a low power universal serial bus are described herein. A universal serial bus port includes a link layer and protocol layer that are compatible with a standard USB2 protocol. The link layer and protocol layer to control a physical layer for transmitting and receiving data on a pair of signal lines. The physical layer includes a fully-digital Low-Speed/Full-Speed (LS/FS) transceiver to transmit and receive data on the pair signal lines using single-ended digital communications on the pair of signal lines.