This invention provides communications systems that enable broadcasting while making use of the simplicity of the prior art and also provides control devices and information processing systems incorporating the communications system. In this invention, chip-select signals are provided for transmitting (TXCSi) and receiving (RXCSi) independently as well as for individual chips as in the prior art. That is, a group of signals indicating whether or not a slave node is selected as the node to transmit signals to a master node and the direction of communications are output from the master node to the slave node.