A circuit device includes first and second physical layer circuits, a bus switch circuit that switches connection between a first bus and a second bus, which are compliant with the USB standard, ON in a first period and OFF in a second period, and a processing circuit that performs processing for transferring a packet in a transfer route constituted by the first bus, the first and second physical layer circuits, and the second bus, in the second period. The second physical layer circuit includes a disconnection detection circuit that detects device disconnection of a device connected to the second bus side. If device disconnection is detected in the second period, the connection between the first bus and the second bus is switched from off to on after a wait period has elapsed from the timing at which the device disconnection was detected.