An information processing system includes a first bus, a second bus, a plurality of modules connected to both buses, a bus arbiter for arbitrating a bus access request of a bus master, and a storage means for storing access data up to a predetermined amount for one of modules when access destination information indicates that said module is the access destination. Each bus master outputs access destination information and when the bus arbiter judges that one of the bus masters issues a bus access request when it performs an access operation, the bus arbiter refers to whether the predetermined amount of access destination information is fully stored in the storage means, and decides whether or not to give a bus access to the bus master.