Abstract: A system and apparatus that include a selectable synchronizer circuit for synchronizing data across asynchronous boundaries are disclosed. The apparatus includes a unit associated with a first clock domain and a synchronizer sub-unit (SSU) coupled to the unit and associated with a second clock domain. The synchronizer sub-unit includes two or more synchronizers and selector logic configured to select one output of the two or more synchronizers.

Abstract: In a system and method for write hazard handling a memory management unit policy is pre-computed for a write request using an address that is at least one clock cycle before data. The pre-computed memory management unit policy is registered and used for controlling a pipeline stall to ensure that a non-bufferable write is pipeline-protected, so that no non-bufferable location is bypassed from within the pipeline, and so that a subsequent non-bufferable read will get data from a final destination. A read request is bypassed only after a corresponding write request is updated in a write pending buffer. The write request is decoded with the write request aligned to data. The write request is registered in the write pending buffer. Arbitration logic is allowed to force the pipeline stall for a region that will have a write conflict. Read requests are stalled to protect against write hazards.

Abstract: A system and method for write hazard handling are described, including a method comprising pre-computing a memory management unit policy for a write request using an address that is at least one clock cycle before data; registering the pre-computed memory management unit policy; using the pre-computed memory management unit policy to control a pipeline stall to ensure that non-bufferable writes are pipeline-protected, ensuring that no non-bufferable locations are bypassed from within the pipeline and all subsequent non-bufferable reads will get data from a final destination; bypassing a read request only after a corresponding write request is updated an write pending buffer; decoding the write request with the write request aligned to data; registering the write request in the write pending buffer; allowing arbitration logic to force the pipeline stall for a region that will have a write conflict; and stalling read requests to protect against write hazards.

Abstract: A digital system is provided with a hierarchical memory system having at least a first and second level cache and a higher level memory. If a requested data item misses in both the first cache level and in the second cache level, a line of data containing the requested data is obtained from a higher level of the hierarchical memory system. The line of data is allocated to both the first cache level and to the second cache level simultaneously.

Abstract: A digital system is provided with a hierarchical memory system having at least a first and second level cache and a higher level memory. If a requested data item misses in both the first cache level and in the second cache level, a line of data containing the requested data is obtained from a higher level of the hierarchical memory system. The line of data is allocated to both the first cache level and to the second cache level simultaneously.