| 摘要 |
A triggering circuit asserts a trigger signal in response to edges of a digital signal conveying a repetitive pattern of edges. The triggering circuit generates first data having a value identifying a position within the pattern of a last occurring edge of the digital signal and generates second data having a value identifying a position of a particular edge within the pattern that is to initiate a next assertion of the trigger signal. The triggering circuit asserts the trigger signal when the first and second data values match and de-asserts the trigger signal when the first and second data do not match. In a repetitive mode of operation, the triggering circuit keeps the second data value constant so that it always asserts the trigger signal in response to the same edge of the pattern. In a sequential mode of operation, the triggering circuit changes the value of the second data each time it asserts the trigger signal so that successive assertions of the trigger signal occur in response to differing edges of the digital signal pattern.
|
