| 摘要 |
PURPOSE:To greatly improve the disturbance of an instruction stream, by prefetching the stream of the branching instruction and having a smooth shift of an instruction stream. CONSTITUTION:The logic product of tags 16a-16e corresponding to the instructions stored in the instruction cues 10a-10d as well as the instruction under execution is set at ''1'', and the conditional code in a state register 18 is not changed by any instruction. As a result, whether or not the branching conditions are satisfied is generally decided by the field constant under the branching instruction and a logic operation of the conditional code. When the branching is satisfied, the branch is transmitted to a branch control circuit 14 along with the contents of a branch address register 12. A branch control circuit 14 cancels the old instruction stream and gives a fetching request of a new instruction stream. The instruction buffers 5-8 are shown in the diagram. |
