In addition, both the four and eight channel devices have an expansion port which allows for another four or eight channel UART to be connected. The interface to the host is shared and the host recognizes the two parts as a single UART device with up to sixteen channels. From a design perspective, this single board design can be used to make a four, eight, twelve or sixteen channel end product. The board layout can be a single effort while creating 4 different end products. This is possible because of the pin compatibility feature of the four and eight channel devices and the expansion port feature on these products. An evaluation board showing this application is also available along with relevant design files.