| 摘要 |
A VISS signal detection method for performing detection of a VISS signal of a video tape includes a step of executing a taking-up process of an interval between edges per level edge of the VISS signal, a step of performing a detection process of a VISS pulse, and a step of performing a detection process of the VISS signal on the basis of result of detection at the VISS pulse detection step. The process of the edge interval taking-in step is set as an interrupt process having highest preference. In the VISS pulse detection step, by making reference to a count value of an edge counter for distributing count values of a timer measuring the edge interval of a phase position detection signal added to the VISS signal used in the edge interval taking-in step, presence and absence of delay in the process of the VISS pulse is detected based on number of occurrence of the edge interval taking-in step occurring up to the VISS pulse detection step. When delay is caused, post process is performed for accurately performing detection process of the VISS depending upon delay and the edge interval taking-in process in the next cycle.
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