METHOD FOR EXECUTING SOFTWARE PROGRAM AND CIRCUIT DEVICE FOR IMPLEMENTING THE METHOD

摘要

This method advantageously utilizes the resources of software programs stored in the external memory connected to the hardware main frame. The circuit device is for implementing this method. The method comprises an initialization routine (X) including a step of switching the bank of BIOS-ROM (13) in the main frame (1) having a CPU (11) to the bank of software programs stored in an external storage (2), a security check routine (Y) in which whether or not a software program is correct is checked, a routine (Z) in which a software program is executed by the CPU (11) in the main frame (1) when the software program is judged to be correct in the security check routine (Y). By resetting the CPU (11) while the bank is at least on the side of the software program which is stored in the external storage (2), the CPU (11) is released from the security check routine (Y), and can execute this software program by the routine (Z).