Once only electrically programmable read-only memory

Abstract

Abstract The memories are programmed by the user. Operating and performance tests cannot therefore be carried out by the manufacturer other than in relation to memory locations constructed in addition to those corresponding to the capacity for which the memory is sold. To access these additional memory locations (16) without having to increase the power of the decoders, the invention ascribes to them an address identical to that of the normal memory locations (24) of the memory plane. When this address is inserted, the additional memory locations are selected at the same time as the normal memory locations with which they are paired. One of the two selections is validated and invalidated by a selection circuit (20, 23) arranged downstream of the corresponding outputs of the decoder. Consequently, full-scale checks can be carried out on the memories. <IMAGE>

Inventors

• 👤 Serge Fruhauf
• 👤 Jean-Marie Gaultier

Bibliographic Details