INFORMATION PROCESSOR

PURPOSE:To prevent the interruption of an instruction reading at the time of a block passing by providing a connection pointer at each block in a buffer storage device for instruction word and having its function to invalidate the temporarily read instruction. CONSTITUTION:A connection pointer 121 is provided at each block I to IV in a buffer storage device for instruction word 102 for predicting successor block. At the time of the block passing, as the block number for the passing destination is read from this pointer and is set to an instruction fetch address counter 101, a temporary reading can be made. When the temporary reading is different from an actual one, a coincidence detector 123 invalidates the temporary reading instruction word. Thus, the utilization factor of the information processor can be improved without an interruption of the instruction reading even at the time of the block passing.