Cache controller

Abstract

A cache controller (40, 60) operable to control a cache (30), the cache (30) comprising a plurality of cache lines, each of the plurality of cache lines being operable to store a plurality of data words and to store validity information indicating that all data words within that cache line are valid is provided. The cache controller (40, 60) comprises a linefill mechanism (65) operable during a linefill operation to write a plurality of data words to a cache line, to provide an indication when each of the plurality of data words has been written to the cache (30) and to set the validity information when all data words in the cache line have been written; and a data word accessing mechanism (45), responsive to a request to access a data word during a linefill operation prior to the validity information being set, to determine from the indication provided by the linefill mechanism whether the data word to be accessed has already been written during the linefill operation and, if so, to provide a signal indicating that the data word is accessible. Since the linefill mechanism (65) need only provide an indication that the data word is accessible from the cache (30) and does not need to store the data word itself, the amount of logic required is considerably reduced whilst still enabling the data word to be accessed.

Dependencies are inferred from the claim text.