Patent US 7,653,786

A power aware front-end unit for a processor may include a UOP cache that disables other circuitry within the front-end unit. In an embodiment, a front-end unit may disable instruction synchronization circuitry, instruction decode circuitry and, optionally, instruction fetch circuitry while instruction look-ups are underway in both a block cache and an instruction cache. If the instruction look-up indicates a miss, the disabled circuitry thereafter may be enabled.