The present invention provides an apparatus and method for accessing data values in a cache and in particular accessing data values in an ānā way set
associative cache. A
data processing apparatus is provided comprising an ānā way set-
associative cache, each cache way having a plurality of entries for storing a corresponding plurality of data values. A
cache controller is provided which is operable on
receipt of an access request for a
data value to determine whether that
data value is accessible within the cache, the cache comprising
cache access logic operable under the control of the
cache controller to determine whether a
data value the subject of an access request is accessible in one of the cache ways. Also provided is a way lookup cache arranged to store an indication of the cache way in which a number of the plurality of data values stored in the cache are accessible. The
cache controller is operable, when an access request for a data value specifies a non-
sequential access, to reference the way lookup cache to determine whether that data value is identified in the way lookup cache and, if so, the cache controller being further operable to suppress the operation of the
cache access logic and to cause that data value to be accessed. The provision of a way lookup cache enables the
power consumption of the cache to be reduced by enabling the operation of the
cache access logic to be suppressed.