INFORMATION PROCESSING UNIT AND PROGRAM

PROBLEM TO BE SOLVED: To provide an information processing unit capable of executing a quick switchover among a plurality of CPU simulators.SOLUTION: An information processing unit comprises: a plurality of CPU simulators 101, 104 that simulate operation of a target CPU for executing a target code; a device simulator 103 that simulates operation of a control target device of the target CPU; and a management unit 102 that simulates operation of an operating system operating at the target CPU, and selects a CPU simulator to execute simulation operation of the target CPU from among the plurality of CPU simulators 101, 104 in response to the simulation operation of the device simulator 103. The management unit 102 executes a switchover to the selected CPU simulator with timing when a system call to the operating system is generated.