MIKROPROZESSORANORDNUNG UND VERFAHREN ZUM BETREIBEN EINER MIKROPROZESSORANORDNUNG

摘要

The system includes a processing unit (2) which is coupled to a memory (8,9) for performing read or write access. A cryptographic unit (81,82) is provided for encrypting and decrypting data values written to or read from the memory. A register (83) and logic elements (85a,b,c) provide a variable encryption key. The register is controlled so that the key is changed if the memory does not contain any more data values to be read out.