An FPGA functions as an activation mode setting circuit for loading activation data stored on a PROM into a circuit setting memory and setting an activation mode when activating the CPU. The FPGA outputs an activation mode setting signal to the CPU, and the CPU is activated in the set activation mode. After the CPU is activated, it follows predetermined processing steps, and performs a control operation to load the circuit setting data stored in a storage section into the circuit setting memory. Thus, the FPGA is constructed as a circuit having a desired function, and also constructed as an activation mode setting circuit when activating the CPU.