Variable delay branch system

Abstract

In a pipeline computer, current instructions executed in sequence are monitored for conditional and unconditional branch commands, as well as the readiness of condition codes, the meeting of branch conditions and split commands. A branch command initiates an interval of delay which affords prefetching target instructions while using pipeline contents to prevent a pipeline break and avoid lost time. Detection of a branch command actuates a register to store a sequence of target instructions. Unless a branch command is conditional, subsequent detection (delayed) of a split command shifts the stored target instructions into operation as the current instructions. For a conditional branch command, a jump or split to the target instructions is performed only if the condition is met. Otherwise the current instruction sequence is restored pending another branch command. Dual instruction registers, program counters and address registers alternate to accommodate branch jumps with considerable time savings by effective programming.