Virtual to physical address translation

An address translation apparatus for translating an explicit address within an address space into a physical address, the explicit address comprised of an index, a TLB index, and an offset, the translation apparatus comprising:

• a space register file having a plurality of space registers, each space register having an indirect address for a corresponding index value;
• and
• a memory organized as N TLB entries, each entry having an entry space tag, a virtual tag, a valid bit, and a physical page number,
• TLB index comparision means for comparing only the TLB index to the virtual tag, and
• means for supplying a physical page number as part of the physical address when the TLB index and the virtual tag corresponding to the physical page number are equal and when the indirect address corresponding to the index and the entry space tag corresponding to the physical page number are equal.

In a virtual memory system having a space register file for storing indirect addresses, a method of speeding TLB translation of an explicit address having base bits and index bits into a physical address, the method comprising:

• providing an entry space tag associated with each entry in the TLB;
• updating an entry space tag whenever the corresponding TLB entry is updated;
• updating the space register file with a new indirect address;
• comparing the new indirect address to a space entry tag;
• and
• storing the results of the comparison in an associated matching bit memory cell for use during a subsequent TLB access.

An address translation apparatus for translating a virtual address into a physical address, the virtual address including an indirect address and an explicit address, the explicit address comprised of a first index and a second index, said apparatus comprising a memory having N entries, each entry having an entry space tag, a virtual tag, and a physical page number, each of said entries including at least

• a first comparator for comparing the second index to the virtual tag;
• a second comparator for comparing the entry space tag of each of the N entries with the indirect address;
• and
• an output unit for outputting a physical page number as part of the physical address when the second index and the virtual tag corresponding to the physical page number are equal and when the indirect address corresponding to the first index and the entry space tag corresponding to the physical page number are equal.