DEVICE AND METHOD FOR DETERMINING A PHYSICAL ADDRESS FROM A VIRTUAL ADDRESS, USING A HIERARCHICAL MAPPING RULE COMPRISING COMPRESSED NODES

摘要

The invention relates to a method for determining a physical address from a virtual address, whereby a mapping rule is implemented between the virtual address and the physical address in the form of a hierarchical tree structure comprising compressed nodes. According to said method, a compression indicator contained in the mapping rule is first read (1300). Then, a section of the virtual address, which is assigned to the node level under consideration, is read (1310). An entry in the node list of the node currently under consideration is determined (1320) using the compression indicator and the virtual address section. The entry that has been determined is read (1330) and the physical address can then be directly determined, if the node level under consideration was the lowest node level in the hierarchy. If there are additional node levels to be processed, the previous steps are repeated for the determination (1340) of the physical address for compressed nodes of lower hierarchy levels, until the lowest node level in the hierarchy has been reached. For addressing schemes, in which the virtual address space is greater than the physical address space, storage space can be saved by the compression of the node lists, which in their uncompressed form contain a number of zero entries, thus providing space for other data.