Patent ID: 6904500

Claim:
A cache controller operable to control a cache, said cache comprising a plurality of cache lines, each of said 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, said cache controller comprising: a linefill mechanism operable during a linefill operation to write a plurality of data words to a cache line, to provide an indication when each of said plurality of data words has been written to said cache and to set said validity information when all data words in said cache line have been written; and a data word accessing mechanism, responsive to a request to access a data word during a linefill operation prior to said validity information being set, to determine from said indication provided by said linefill mechanism whether said data word to be accessed has already been written during said linefill operation and, if so, to provide a signal indicating that said data word is accessible, wherein said request to access a data word includes word information identifying which of said plurality of data words is to be accessed and said data word accessing mechanism is operable to compare said word information with said indication to determine whether said data word has been written.