Patent ID: 7080170

Claim:
An apparatus comprising: a buffer comprising a plurality of entries, wherein the plurality of entries are grouped into a plurality of non-overlapping groups, at least two entries included in each group; a plurality of age vectors, each of the plurality of age vectors corresponding to a different one of the plurality of groups, and wherein the age vector corresponding to a first group of the plurality of groups indicates which of the other groups of the plurality of groups contain data that is older than the data in the first group; and a control circuit coupled to the buffer, wherein the control circuit is configured, responsive to data being provided to the buffer to be written to at least a first entry of the plurality of entries, to generate a first age vector of the plurality of age vectors, the first age vector corresponding to a given group of the plurality of groups that includes at least the first entry, wherein the first age vector is indicative of which of the plurality of entries contain data that is older than the data being written to at least the first entry, and wherein the control circuit is configured to select a selected entry of the plurality of entries for reading responsive to the plurality of age vectors, the selected entry being the entry of the plurality of entries that: (i) has an attribute used to select the selected entry, and (ii) other entries indicated as storing older data in the age vector corresponding to the selected entry do not have the attribute.