| 摘要 |
PURPOSE:To prevent a program from being decoded and stolen, by constituting a system by building in an address conversion circuit being connected to a microprocessor chip, and a circuit which sets and fixes the converting function of the conversion circuit, with the microprocessor chip. CONSTITUTION:The address terminals A0-An of the microprocessor chip 11 are connected to an input part on one side of the exclusive OR circuits Ex0-Exn of the address conversion circuit 13, and the voltage of a level of 0, or of a level of 1, is supplied from a conversion function generation circuit 12 to the input part on the other side, and the chip 11, the circuits 12 and 13 are built in the microprocessor. |
