Patent ID: 7983332
Filing Date: 2011-07-19
Classification: G01R,H04L

Abstract:
1. A digital oscilloscope capturing for display a portion of a digital signal containing an eye violation, comprising: an acquisition circuit for acquiring samples of a digital signal under test; mask defining circuitry for defining a mask area within a unit interval of said signal under test; a violation detector circuit detecting said eye violation in said portion of said digital signal within said unit interval as said digital signal is being acquired; said detector generating a violation signal when said digital signal crosses into said mask area during said unit interval; and a display unit for displaying said digital signal; wherein said mask defining circuitry includes a threshold comparator circuit, said threshold comparator circuit receiving said digital signal, a high threshold level signal and a low threshold level signal and providing as outputs high data and low data; and clock deriving circuitry deriving an early clock and a late clock from a reference clock; said high and low thresholds levels and said early and late clocks defining said mask as a rectangle within said unit interval; and wherein said violation detection receiving as inputs said high data, said low data, said early clock and said late clock and providing as an output said violation signal, said violation signal being a trigger signal, said trigger signal causing said digital oscilloscope to capture said data from said digital signal that is related to said violation, for processing and display on said display unit.