Patent ID: 7389449

Claim:
An apparatus for repeatedly asserting a trigger signal in response to a digital signal conveying repetitive instances of a pattern of edges, the apparatus comprising: a first circuit for generating first data in response to each edge of the pattern of edges, the first data having a value identifying a position of said each edge within the pattern, a second circuit for generating 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, and a third circuit for asserting the trigger signal when the first and second data have matching values and de-asserting the trigger signal when the first and second data do not have matching values wherein the second circuit operates alternatively in one of sequential and repetitive triggering modes selected by input mode control, wherein when the second circuit operates in the sequential mode it changes the value of the second data when it asserts the trigger signal, and wherein when operating in the repetitive mode, the second circuit does not change the value of the second data when it asserts the trigger signal.