Abstract:
Rescheduling multiple micro-operations in a processor using a replay queue. The processor comprises a replay queue to receive a plurality of instructions and an execution unit to execute the plurality of instructions. A scheduler is coupled between the replay queue and the execution unit. The scheduler speculatively schedules instructions for execution and dispatches each instruction to the execution unit. A checker is couple to the execution unit to determine whether each instruction has executed successfully. The checker is also coupled to the replay queue to communicate to the replay queue each instruction that has not executed successfully.
Abstract:
Breaking replay dependency loops in a processor using a rescheduled replay queue. The processor comprise a replay queue to receive a plurality of instructions, and an execution unit to execute the plurality of instructions. A scheduler is coupled between the replay queue and the execution unit. The scheduler speculatively schedules instructions for execution and increments a counter for each of the plurality of instructions to reflect the number of times each of the plurality of instructions has been executed. The scheduler also dispatches each instruction to the execution unit either when the counter does not exceed a maximum number of replays or, if the counter exceeds the maximum number of replays, when the instruction is safe to execute. A checker is coupled tot he execution unit to determine whether each instruction has executed successfully. The checker is also coupled to the replay queue to communicate to the replay queue each instruction that has not executed successfully.
Abstract:
Replay instruction morphing. One disclosed apparatus includes an execution unit to execute an instruction. A replay system replays an altered instruction if the execution unit executes the instruction erroneously.
Abstract:
A multiprocessing system maintains cache coherency during a reduced power mode of operation. The multiprocessing system has a first and a second processor coupled to the bus to perform data transactions with the main memory. During the reduced power mode of operation, the internal clock signal of the second processor is decoupled from a portion of the internal logic of the second processor while remaining coupled to a portion of the internal logic of the second processor that is used to monitor and respond to the traffic on the external bus to maintain cache coherency. During the reduced power mode of operation, the second processor continues to perform snoop and write-back processes to maintain a cache coherent multiprocessing system.
Abstract:
A method and apparatus for upgrading a uniprocessor system to a multiprocessing system simply by the insertion of a second microprocessor integrated circuit. The computer system is provided with an upgrade socket for receiving the second processing unit, as well as a private communications bus between the upgrade socket and the existing processor for handling interprocessor communications, bus arbitration and cache coherency, etc. The addition of the second processor is transparent to the system which maintains its memory management unit and caching system and other arrangements as though it were still a uniprocessing system. Therefore, an inexpensive method and apparatus are provided for greatly enhancing the speed of a uniprocessing system to that of a multiprocessing system without the cost traditionally associated with multiprocessing systems.
Abstract:
A multiprocessing system maintains cache coherency during a reduced power mode of operation. The multiprocessing system has a first and a second processor coupled to the bus to perform data transactions with the main memory. During the reduced power mode of operation, the internal clock signal of the second processor is decoupled from a portion of the internal logic of the second processor while remaining coupled to a portion of the internal logic of the second processor that is used to monitor and respond to the traffic on the external bus to maintain cache coherency. During the reduced power mode of operation, the second processor continues to perform snoop and write-back processes to maintain a cache coherent multiprocessing system.
Abstract:
Replay instruction morphing. One disclosed apparatus includes an execution unit to execute an instruction. A replay system replays an altered instruction if the execution unit executes the instruction erroneously.
Abstract:
Rescheduling multiple micro-operations in a processor using a replay queue. The processor comprises a replay queue to receive a plurality of instructions and an execution unit to execute the plurality of instructions. A scheduler is coupled between the replay queue and the execution unit. The scheduler speculatively schedules instructions for execution and dispatches each instruction to the execution unit. A checker is coupled to the execution unit to determine whether each instruction has executed successfully. The checker is also coupled to the replay queue to communicate to the replay queue each instruction that has not executed successfully.
Abstract:
An apparatus in a first processor includes a first data structure to store addresses of store instruction dispatched during a last predetermined number of cycles. The apparatus further includes logic to determine whether a load address of a load instruction being executed matches one of the store addresses in the first data structure. The apparatus still further includes logic to replay to the respective load instruction if the load address of the respective load instruction matches of the store addresses in the first data structure.