Patent ID: 11907301
Assignee: ARM LIMITED
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. An apparatus comprising:
processing circuitry to perform an operation based on information specified in a control table stored in a memory system, the control table comprising a plurality of entries each specifying a first limit address and one of a second limit address and a size for calculating the second limit address, wherein the first limit address and the second limit address are addresses within a same address space and identify limits of a corresponding address region of variable size within the address space, where the plurality of entries are arranged in the control table in order of the first limit address, and where encoding of the control table entries permits there to be gaps between the corresponding address regions defined by successive entries of the control table; and
table lookup circuitry to perform a binary search procedure to identify whether the control table comprises an entry corresponding to a query address, the binary search procedure comprising a plurality of search window narrowing steps for narrowing a current search window of candidate entries of the control table to a narrower search window comprising fewer candidate entries; in which:
in a given search window narrowing step, the table lookup circuitry is configured to narrow the current search window based on a comparison of the query address against the first limit address of a selected candidate entry of the current search window, independent of said one of the second limit address and the size of the selected candidate entry; and
following a final search window narrowing step which narrows the current search window to a single candidate entry of the control table, the table lookup circuitry is configured to determine that said single candidate entry is the entry corresponding to the query address when the query address is within the corresponding address region defined by the first limit address and said one of the second limit address and the size of said single candidate entry.