摘要 |
A method for enciphering and deciphering instructions in a microcomputer and a microcomputer for effecting the same, in which, an instruction is coded into at least two types of instruction codes and stored in a storage unit and in which, under the control of discriminating circuit for discriminating the coded format, each instruction code is decoded by one of at least two decoders in accordance with one of at least two decoding formats, so that the stored software is prevented from being learned by third persons. |