Abstract: An elapsed cycle number during the predetermined period of the inputted clock source is counted using the clock reference signal as a yardstick, a frequency of the clock source is computed based on an elapsed cycle number obtained by counting, control timing of various interfaces relating to the CPU is adjusted and an interruption generating interval in which interruption is generated regularly by the CPU so that adjustment of control timing of various interfaces and setting of a timer interruption interval during the OS operation in accordance with a frequency of the clock source without performing OS modification such as rebuilding and the like.

Abstract: An elapsed cycle number during the predetermined period of the inputted clock source is counted using the clock reference signal as a yardstick, a frequency of the clock source is computed based on an elapsed cycle number obtained by counting, control timing of various interfaces relating to the CPU is adjusted and an interruption generating interval in which interruption is generated regularly by the CPU so that adjustment of control timing of various interfaces and setting of a timer interruption interval during the OS operation in accordance with a frequency of the clock source without performing OS modification such as rebuilding and the like.

Abstract: In the initialization of a multiprocessor system, device history information containing mounting position information indicating a mounting position of a CPU board supplied from a history information supplying unit is stored in a nonvolatile storage unit in the CPU board capable of storing plural pieces of device history information, so that the mounting position information on each of CPU boards can be accurately and automatically recorded in each CPU board and the history of the mounting position of the CPU board can be recorded and managed on a CPU board by CPU board basis.