A cache memory comprising: 1) a tag array comprising a plurality of tag entry locations that are accessed by R of the M least significant bits of an N-bit received address and stored an address tag comprising the (N-M) most significant bits of the N-bit received address. The cache memory also comprises 2) cache hit comparison circuitry for comparing the (N-M) most significant bits of an N-bit received address with an address tag and generating a HIT signal if a match occurs, and 3) tag array test circuitry for testing the operation of the tag array and the cache hit comparison circuitry.