Patent ID: 8660173

Claim:
A video data processing apparatus comprising: processing circuitry configured to perform video processing operations requiring access to video reference frames; translation circuitry, responsive to a memory access request for reference frame pixel data issued by said processing circuitry, configured to perform a translation process on said video reference frame information, wherein said memory access request specifies video reference frame information, said video reference frame information including video reference frame identifier bits; a memory management unit configured to translate a virtual address corresponding to said video reference frame information into a physical address indicating a storage location in external memory of said reference frame pixel data, said memory management unit having an internal storage unit having a plurality of entries wherein indications of corresponding virtual address portions and physical address portions are stored, said memory management unit configured to index into at least one selected entry of said internal storage unit in dependence on at least one hash value derived from said virtual address using at least one hash function, wherein said memory management unit is configured, if said at least one selected entry does not correspond to said virtual address, to retrieve from a page table stored in said external memory a replacement entry corresponding to said virtual address, wherein said translation circuitry is configured to perform said translation process such that a set of input values for said at least one hash function comprises said video reference frame identifier bits, said at least one hash function produces different hash values for two memory access requests for the same spatial coordinate information of two different video reference frames.