| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an automatic phase difference regulating system in which the accuracy of the phase regulation between cards is improved when a phase synchronization is performed between the reference clock supply cards of a redundant structure. <P>SOLUTION: The reference supply clock cards (10) and (20) calculate the time difference of a net clock (1) supplied from a host apparatus and a self-card generating timing signal, decide a delay set value from its difference, perform a phase difference regulation, hence can regulate the phase difference by individual combinations, and can deal with the unevenness of a buffer delay amount. The phase difference automatic regulation is performed at each predetermined period, and hence can deal with a buffer delay time change due to a temperature change or voltage change and a delay in PLL units (11), (21). Even at a card switching time, a reference clock can be stabilized and supplied. Since a measurement of the phase difference between a plurality of cards is eliminated at an evaluating time, and hence a working man-hour can be reduced. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
