PIPE LINE CONTROL SYSTEM

PURPOSE:To continuously read out an instruction even after crossing a block without waiting for the detection of a hit/mishit by canceling the instruction read out after crossing the block at the time of detecting the mishit. CONSTITUTION:An instruction word read out from a buffer storing device 102 after crossing the block is temporarily read out as temporary read, and a temporarily read signal 123 is circulated onto temporarily read flags 113 to 116. The hit/mishit is detected by a hit/mishit detector 119, and a signal 121 is outputted, a stage canceling circuit 120 outputs a signal 122 when it receives the mishit, and cancels the stage whose temporarily read flag is at '1'. That is, without waiting for the output from the detector 119 at the time of crossing the block, an instruction fetch address counter 101 specifies and reads out the next address, and at the time when the mishit is detected, the instruction shifted on the stage is canceled. Thus the interval between instruction reading times due to the detection of the hit/mishit is eliminated.