ATM Bus System

An ATM bus 11 is a bus for performing data transfers in an asynchronous transfer mode, while a control bus 8 is a bus for transferring control signals sent out by a central control section 1 in order to control bus users 10a ~ 10d. The bus users 10a ~ 10d and a bus arbitration circuit 12 are connected to this ATM bus. The bus users 10A ~ 10d are ATM bus users. When the bus users 10a ~ 10d simultaneously issue bus use requests, the bus arbitration circuit 12 selects a single bus use request from among these requests. Then, all of the bus users are sent data identifying the bus user which issued the selected bus use request. As a result, only the selected bus user begins a data transfer operation using the ATM bus 11.