ADDRESS CONTROLLER

PURPOSE:To prevent deterioration of the efficiency caused by a branch processing at the time of processing of a CPU by detecting a branch instruction when a program is being executed. CONSTITUTION:When a loop of a prescribed address range is repeated by executing a branch instruction existing in a program in a memory 2, and address controller 6 detects loop start and end addresses by an operation of a CPU 1, and recognizes a loop variable. The loop is detected from the operation of the CPU 1, and until the loop is ended by the loop variable, the controller 6 continues an access of an address in the loop. In case of executing a branch instruction in the loop, an access control of the address uses a value of a program counter 3 which has been changed by said instruction, as an address value. At the time of having shifted to the execution of the instruction in the loop, the address in the loop is brought to access again by the controller 6. When the loop is ended, the controller 6 substitutes the address whose loop has been ended in the counter 3 in the CPU 1.