Provided are a communication system and a method of restoring the communication system. The communication system includes a master device for transmitting a reference clock through a clock line, transmitting and receiving data through a data line, and requesting and receiving input data and error detection data, and a slave device for detecting human touch input data, transmitting and receiving the data in synchronization with the reference clock or generating and transmitting the input data, and transmitting the error detection data in response to the request for error detection data. Here, the master device compares stored error detection data with the received error detection data and initializes the slave device when the stored error detection data is not the same as the received error detection data. Therefore, in the master-slave communication system capable of automatic restoration from a malfunction and the method of restoring the communication system, a master device recognizes malfunction of a slave device having a volatile storage due to its surroundings, initializes the slave device, and thus can restore the slave device to its normal operating state.