Abstract: A universal serial bus (USB) transmission system for transmitting a monitor control signal and a data signal from a monitor system to a main frame is provided. The universal serial bus transmission system separately includes a universal serial bus interface IC and a monitor controller IC between which the monitor control signal and the data signal are transmitted through a low-speed transmission interface, thereby reducing costs for handling electromagnetic interference (EMI). Furthermore, the universal serial bus interface can be modularized to allow the monitor system to serve as a general monitor system or a USB monitor system, thereby increasing the utility of the monitor system.

Abstract: An electromagnetic safety (EMS) enhancement circuit is provided for a USB (Universal Serial Bus) system, which can simulate an unplugging and replugging action so as to ensure continuous operation of the USB device after being disconnected from the USB interface due to electromagnetic interferences. The EMS enhancement circuit utilizes an EMS detection unit to detect the EMS condition of the data communication between the USB device and the USB interface; if abnormal, the EMS detection unit will output an overflow signal to a resume-control unit.