Method and apparatus for aligning an instruction boundary in variable length macroinstructions with an instruction buffer

摘要

A circuit and method for supplying and aligning a block of multiple variable length macro instructions to an instruction buffer. Only one cycle is required to align and rotate the block of instruction code. A last byte vector of the instruction code in the instruction buffer is scanned from the last byte in a direction from back to front, thereby saving time. Rotating begins immediately so that a next block of instruction code is available in a next cycle. The block is stored in the instruction buffer after all macroinstructions therein have been steered to the decoder.