BICMOS cache TAG having small signal exclusive OR for TAG comparison
 A cache TAG RAM (25) includes a TAG array (26), a small signal exclusive OR logic circuit (33, 34), a sense amplifier (36, 37), and another exclusive OR logic circuit (30, 31). A comparison of a stored TAG address to the input address signal is made by the small signal exclusive OR logic circuit (33, 34) to provide a hit signal very quickly. The stored TAG address that is lost during the exclusive OR operation is recovered by performing another exclusive OR on the match information and the input address signal. By using a small signal exclusive OR circuit to perform a comparison early, the hit signal can be generated very quickly. 
Motorola Inc.
G
G06F
inventional
Mark D. James C.
Bader Lewis