Patent ID: 8127351

Claim:
A program execution control apparatus comprising: a memory interface for storing thereinto a program; a detection unit configured to detect a check time instant for checking whether or not said program is illegal; a check unit configured to check whether or not illegality is present in said program at said check time instant; a control unit configured to control to execute a program having no illegality, which is judged by said check unit; an execution unit for executing said program having no illegality; and a judging unit configured to judge, when the check unit determined that said program has illegality, that said program having the illegality is executed if an address of an instruction fetch corresponds to an address for which said program having illegality is executable despite of the illegality and that said program having the illegality is not executed if the address of an instruction fetch corresponds to an address for which said program having illegality is not executable due to the illegality, wherein: said control unit controls to execute said program having the illegality, which is judged to be executed, and the illegality is detected when a value resulting from a summation of data of the program is different from a predetermined normal value.