Pin sharing device and method thereof for a universal asynchronous receiver/transmitter module and a universal serial bus module

摘要

A pin sharing device for a UART module and a USB module includes a first port coupled to a first terminal of the USB module, a second port, a first multiplexer, a second multiplexer, a first switch and a second switch. The first multiplexer is utilized for selectively coupling the first port or a signal generator to a receiving terminal of the UART module. The second multiplexer is utilized for selectively coupling a transmitting terminal of the UART module or a second terminal of USB module to the second port. The first switch and the second switch are utilized for pulling up voltage level of the first port and voltage level of the second port when the UART module and the USB module is not coupled to any UART device or USB host device. Therefore, a number of pins for the UART module and the USB module can be reduced.