A master device for performing data transmission and reception with a slave device includes: a data transmission and reception circuit for performing transmission of data to the slave device and reception of data from the slave device via a first transmission path in a time division manner; and a control circuit wherein when data is transmitted or received, the control circuit provides a clock signal synchronous with the data to the slave device via a second transmission path, the control circuit provides a signal for setting a state of the slave device, to the slave device via a third transmission path while setting the clock signal at a first level, and the control circuit provides a signal for serving as a trigger for the slave device performing a predetermined operation, to the slave device via the third transmission path while setting the clock signal at a second level different from the first level.