A chip includes a receiving, a transmission, a control, and a switch circuit. The receiving circuit is operated at a first voltage and receives a first data. The transmission circuit is operated at the first voltage. Under general mode, the control circuit is operated at a second voltage and generates a second data to the transmission circuit according to the first data. The control circuit includes a first clock source configured to provide a first clock under general mode. The control circuit is operated according to the first clock. Under general mode, the switch circuit is operated at the first voltage, and controls the second voltage to pause the second voltage supplying to the control circuit to enter sleep mode. Under sleep mode, the switch circuit controls the supply of the second voltage to the control circuit according to the first data to return to general mode.