Abstract: A simulation method and a simulation system are provided. The simulation system may be divided into an execution model and a processor model based on a JIT emulation engine. The execution model can call the JIT emulation engine to execute instructions, and obtain influence of instructions on a processor architectural status. The processor model may simulate an internal process of a target processor and determine whether to start/end a speculation. The execution model and the processor model may interact through a specific protocol. After the speculation is started, the simulation method may store an application running scene when the speculation is started, and redirect influence of speculation instructions on a memory to a memory snapshot. After the speculation is ended, the simulation method may also restore the application running scene to a status before the speculation is started, and cancel influence of the speculation instructions on the memory.

Abstract: A simulation method and a simulation system are provided. The simulation system may be divided into an execution model and a processor model based on a JIT emulation engine. The execution model can call the JIT emulation engine to execute instructions, and obtain influence of instructions on a processor architectural status. The processor model may simulate an internal process of a target processor and determine whether to start/end a speculation. The execution model and the processor model may interact through a specific protocol. After the speculation is started, the simulation method may store an application running scene when the speculation is started, and redirect influence of speculation instructions on a memory to a memory snapshot. After the speculation is ended, the simulation method may also restore the application running scene to a status before the speculation is started, and cancel influence of the speculation instructions on the memory.

Abstract: A carrier head for a chemical mechanical polishing apparatus includes a retaining ring having a flexible lower portion and a rigid upper portion. A shim can be inserted between the retaining ring and a base of the carrier head to improve the retaining ring lifetime. A seal may be inserted between the retaining ring and a flexible membrane to seal the chamber between the flexible membrane and the base.