Universal serial bus and method for transmitting serial clock and serial data signals during power-saving mode

摘要

A universal serial bus (USB) with a power-saving mode and an operating method thereof are provided. When the USB peripheral is coupled to the USB host, the USB host core logic of the USB host transmits an inquiry request via a USB transceiver to inquire whether or not the USB peripheral supports the power-saving mode. The core logic of the USB peripheral responds via the USB transceiver that the power-saving mode is supported. Then the USB peripheral is off-line and then is shifted to be on-line for operating the power-saving mode. The USB host is also switched to the power-saving mode. Under the power-saving mode, the data are respectively transceived by the serial transceivers. The clock frequency of the serial transceiver can be adjusted according to the request of data transmission.