PURPOSE: To attain the high speed rise of a data processing system by providing a means to output an opportunity signal at an opportunity when an initial self-diagnosis should be executed.

CONSTITUTION: When a specified condition is satisfied out of all rising opportunities, an opportunity condition setting means 1 outputs a signal. At the time of rising the data processing system, an opportunity condition judging means 4 inputs the output signal of the opportunity condition setting means 1, judges the propriety of a request, and executes a diagnosis when the signal is to request the diagnosis of hardware. An opportunity condition clear means 2 inputs the signal to request the diagnosis and since it clears the signal, in the next opportunity generation, the signal is judged as one not to request the execution of the diagnosis and the diagnosis is not executed. When it is necessary to execute the diagnosis of the hardware, a diagnosis execution designating means 3 executes a designation and the presence and absence of the designation is judged in a diagnosis designation judging means 5. When there is the designation, the diagnosis is executed and when the designation is absent, a data processing is started. Thus, the high speed rise of the data processing system is made possible.