The S0MODE bit in the SCON0 register is used to configure the mode of operation. There are two modes available in this particular peripheral. The 8-bit mode and the 9-bit mode. So far, this lecture has covered the 8-bit UART with Variable Baud Rate (Mode 1) and will now look at programming the UART peripheral for 9-bit mode. There are some applications that require multiple UARTs to be connected as a bus. The 9-bit mode is used to signal multiprocessor communications such that the ninth bit gets set to indicate that the data received represents an address. A device with a matching address can accept the data and provide the appropriate action or response. All other devices that don’t have a matching address simply discard the data. The 8-bit mode is the most common mode and is used as the data representation for the RS232 standard.