Abstract: A pulse voltage with its frequency set at approximately 1 MHz and achieving a level of approximately 1V on the high level side and a level of −5˜−7V on the low level side is applied to the P-type well 123. When 1V is applied to a P-type well 123, the resulting forward bias causes electrons to be injected from a source 116 and a drain 117 into the channel (P-type well 123) (a). As the voltage applied to the P-type well 123 changes to −5 V, a depletion layer 124 is formed at the channel. At the depletion layer 124, the electrons are accelerated toward a tunnel oxide film 111 (b). The electrons having been accelerated in the channel are injected into the tunnel oxide film 111, are allowed to move inside the tunnel oxide film 111 by the electrical field at the tunnel oxide film 111 and are finally trapped at a floating gate 113.

Abstract: A semiconductor associative memory device directly supplies status signals each representative of matching state or mismatching state from regular/redundant memory words to an address generator for generating a preliminary address signal representative of the regular/redundant memory word supplying the status signal representative of the matching state, and an address correcting system examines the preliminary address signal to see whether or not the preliminary address signal is representative of one of the regular/redundant memory word affected by a replacement of a defective regular memory word with the redundant memory word; when the preliminary address signal is representative of the regular/redundant memory word, the address correcting system generates a formal address signal representative of the address of one of the regular memory words expected to store the data code matched with a given data code if all the regular memory words are excellent at storing data codes.