Device for enabling the use of the contents of memory areas of an electronic microprocessor system

摘要

A decision circuit receives input addresses of instructions to be executed and data addresses to which the instructions are to be applied. The decision circuit either allows the execution of the instruction or prohibits the execution of the instruction if the instruction leads to a false operation or to a fraudulent attempt to divulge the system contents. A buffer register stores the instruction addresses and subsequently presents them to the decision circuit simultaneously with the data addresses. This device applies particularly to the protection of electronic integrated circuit memory cards.