Patent ID: 7480329
Filing Date: 2009-01-20
Classification: H04L

Abstract:
1. A method of measuring Data Dependent Jitter for a digital signal in a System Under Test, comprising the steps of: (a) processing consecutively sampled values of an instance of an arbitrary Test Pattern in the digital signal to produce an Acquisition Record; (b) measuring times of occurrence of consecutive edges in the Acquisition Record to form a corresponding Original Time Interval Error Record; (c) specifying, via a Template, a collection of Descriptors of digital signal behaviors with which amounts of Data Dependent Jitter are to be associated, the Template specifying at least one bit position or signal value transition that is both A) not adjacent to a reference bit location or signal value transition of the Template, and B) not contiguous with a set of bit positions or signal value transitions of the Template that include a bit position or signal value transition that is adjacent to the reference bit location or signal value transition of the Template; (d) inspecting the Acquisition Record of Step (a) to find instances of a selected Descriptor chosen from among those specified in Step (c); (e) identifying in the Original Time Interval Error Record a respective Time Interval Error value associated with each instance of the selected Descriptor found in Step (d); (f) subsequent to an instance of Step (e), finding a Metric that is the average of the Time Interval Errors values associated with the found instances of the selected Descriptor in Step (d); (g) repeating Steps (d), (e) and (f) for a different selected Descriptor until Steps (d), (e) and (f) have been performed for at least two Descriptors in the collection thereof specified in Step (c); and (h) storing each Metric found in Step (f) in a table indexed by the selected Descriptor for which it was found.