Instruction window

An instruction window in computer architecture refers to the set of instructions which can execute out of order in an out-of-order speculative CPU.

In particular, in a conventional design, the instruction window consists of all instructions which are in the re-order buffer (ROB). In such a processor, any instruction within the instruction window can be executed when its operands are ready. Out-of-order processors derive their name because this may occur out-of-order (if operands to a younger instruction are ready before those of an older instruction).