Patent ID: 7302365
Filing Date: 2007-11-27
Classification: G01R

Abstract:
1. Apparatus for performing an eye scan, comprising: a receiver for receiving input signals; an equalizer for processing said input signals; a data sampler for sampling said processed input signals at certain sampling points to produce a data output, said data sampler being controlled by a clock signal; an edge sampler for detecting the edges of the processed input signal; an early/late voter for deciding whether a current sampling point needs to be advanced or retarded wherein said early/late voter passes an Up/Down signal to an interpolator for maintaining said clock signal, said interpolator acting on said Up/Down signal to adjust the clock signal by stepping it forward or backward according to control need, so that said sampling point can be advanced or retarded; and an accumulator for adding an eye scan sampling point offset to the Up/Down signal prior to its reception at the interpolator wherein the offset changes a known input signal from one binary state to another, wherein a boundary condition for the eye scan is determined.