US 2006/0188045 A1Published application

Method for selecting and extracting an eye diagram opening for subsequent processing

AssigneeAgilent Technologies, Inc.

InventorRichard Nygaard

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Abstract

Measurements for an eye diagram of a signal of interest are placed in a data structure that is examined to locate an eye opening of interest. The eye opening of interest has already been, or is subsequently, normalized into figure of merit units related to the operational voltage and timing requirements of the data receiver for that signal. The locations within the normalized eye opening may be taken as center locations for trial symmetric shapes that start out small and are enlarged until they first include locations not part of the normalized eye opening. The center of a largest such shape is mapped back into the units of the original eye diagram as optimum sampling parameters for data analysis equipment that uses the receiver to sample the signal once per unit interval to discover logical value. An alternative is to repeatedly remove the ‘outer layer’ of the normalized eye opening until only one location remains.

Claims7

Dependent claims

A method of extracting an eye opening from an eye diagram for a digital signal, the method comprising the steps of:

(a) storing an eye diagram of the digital signal in a first data structure having a first dimension indexed by a first collection of consecutive ordinal values each representing a discrete value of time and having a second dimension indexed by a second collection of consecutive ordinal values each representing a voltage, the first data structure containing a NULL indication in locations corresponding to time and voltage combinations that did not occur for the digital signal and containing a non-NULL indication in other locations;
(b) reading from the first data structure at plurality of selected locations to discover at least one NULL indication;
(c) separately traversing the data structure beginning at each NULL indication found in step (b) to discover collections of locations containing the NULL indication that are left-right and top-down adjacent to each other and to such each NULL indications found in step (b);
(d) counting the number of NULL indications associated with each separate traverse of step (c);
(e) identifying a largest count for step (d);
(f) storing non-NULL indications into all locations of a second data structure large enough in each dimension to contain a rectangular region for the locations traversed in step (c) whose count of for step (d) was identified as a largest count in step (e) ;
and
(g) storing NULL indications into those locations of the second data structure corresponding to the collection of locations discovered in step (c) and for which the count of step (d) was identified as a largest count in step (e).

5 more elements

Dependencies are inferred from the claim text.