BUS ACQUIRING SYSTEM

PURPOSE:To adjust the bus access by the priority decision and to eliminate to use two buses or above by one module with the adjustment by synchronizing the adjusting means to constitute the module and adjusting the access. CONSTITUTION:Arbitrating parts 2 and 11 are connected to either of buses 10 and 19. A control part 1, when the bus access is executed, adjusts to acquire the buses 10 and 19 by the arbitrating parts 2 and 11 with arbitrating instruction signals 3 and 12, and after the use of the bus is completed, outputs bus releasing signals 5 and 14. A control part 1, when either of the arbitrating parts 2 and 11 acquire the bus, makes insignificant other side arbitrating instruction part 3 or 12 and executes the access of the acquiring bus. The control part 1, even when either of bus acquiring signals 4 and 13 outputted from the arbitrating parts 2 and 11 comes to be significant, controls to use either of the buses 10 and 19.