Patent ID: 7603025

Claim:
A copy protection pulse detection circuit, comprising: a pulse detector, wherein the pulse detector receives an input video signal and sets a pulse detect indication each time a pulse that exceeds a first threshold is detected in the input video signal; an accumulator operably coupled to the pulse detector, wherein the accumulator counts a number of pulses received in each field of the input video signal to produce an accumulated count; a field pulse comparator operably coupled to the accumulator, wherein the field pulse comparator compares the accumulated count for each field with a second threshold, wherein when the accumulated count exceeds the second threshold for a field, the field pulse comparator asserts a positive count indication for the field; a decision counter operably coupled to the field pulse comparator, wherein the decision counter increments a decision count when the positive count indication is asserted for a field and decrements the decision count when the positive count indication is not asserted for a field; and a decision comparator operably coupled to the decision counter, wherein when the decision count reaches a high threshold, the decision comparator sets a pulses detected indication, wherein when the decision count reaches a low threshold, the decision comparator clears the pulses detected indication.