| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a clock signal generating semiconductor device, a system board and an operation control method that can supply a plurality of clock signals having a continuously constant phase relation to functional devices on the system board by accommodating prevention of an erroneous operation due to an environmental change such as a fluctuation in temperature or source voltage without an increase in circuit scale. <P>SOLUTION: The clock signal generating LSI mounted on a PC motherboard functions as a clock generation part 1 for devices such as a CPU 31, an SDRAM 32, an AGP 33 and a PCI 34 of a system part 2, and has programmable delay circuits 15 to 18. Every time power is input, an error occurs or a fixed time elapses, an operation test program executed by an operation test part 41 of the CPU 31 executes a system operation test, and according to the result, delay times of the programmable delay circuits 15 to 18 are repeatedly reset to optimize the phases of clock signals. <P>COPYRIGHT: (C)2004,JPO</p> |
