Abstract: An instrument uses a marker as a passive element for indicating measurement and reference points and also uses the marker to enter data. In response to a user placing the marker on a graph and selecting a predetermined key on a keypad of the instrument, the instrument enters at least one value represented by the marker into an active table.

Abstract: A method and an apparatus for scaling display for displaying an input signal are disclosed, the method and apparatus particularly being useful for displaying return-to-zero signals. The technique includes a first step of sampling the signal. The sampled signal is searched for a zero space pattern. Then, a first zero space is located and a second zero space, following the first zero space, is located. A bit period of the input signal is calculated. Finally, the input signal is displayed using the calculated bit period as the basis for a scale.

Abstract: Auto-skew alignment of high-speed eye diagrams of a pair of differential signals defines a figure of merit containing time integrals of mathematical functions dependent on magnitudes of the differential signals and related skew, then calculating an optimized skew value that minimizes the figure of merit. Optimally integrals are performed over a random time interval including at least two consecutive bit periods of the differential signals. Calculations include coarse search for optimum skew and fine search using an adaptively decreasing fine skew interval. Data acquisition and control hardware includes paired independent skew circuits and paired sampling circuits coupled to a timebase generator and a processing unit, which performs calculations in accordance with an auto-deskew algorithm. The accuracy of the optimized skew value is limited only by hardware skew resolution which in present implementations is less than or equal to one picosecond.

Abstract: Eye diagram masks may be specified by physical parameters directly related to waveform parameters in place of geometric representations, resulting in a more user friendly way to create custom eye masks. NRZ eye masks may be specified by the user using five parameters while RZ eye masks may be specified by the user using seven parameters.

Abstract: Auto-skew alignment of high-speed eye diagrams of a pair of differential signals defines a figure of merit containing time integrals of mathematical functions dependent on magnitudes of the differential signals and related skew, then calculating an optimized skew value that minimizes the figure of merit. Optimally integrals are performed over a random time interval including at least two consecutive bit periods of the differential signals. Calculations include coarse search for optimum skew and fine search using an adaptively decreasing fine skew interval. Data acquisition and control hardware includes paired independent skew circuits and paired sampling circuits coupled to a timebase generator and a processing unit, which performs calculations in accordance with an auto-deskew algorithm. The accuracy of the optimized skew value is limited only by hardware skew resolution which in present implementations is less than or equal to one picosecond.

Abstract: Eye diagram masks may be specified by physical parameters directly related to waveform parameters in place of geometric representations, resulting in a more user friendly way to create custom eye masks. NRZ eye masks may be specified by the user using five parameters while RZ eye masks may be specified by the user using seven parameters.

Abstract: A method and apparatus for scaling display for displaying an input signal are disclosed, the method and apparatus particularly being useful for displaying return-to-zero signals. The technique includes a first step of sampling the signal. The sampled signal is searched for a zero space pattern. Then, a first zero space is located and a second zero space, following the first zero space, is located. A bit period of the input signal is calculated. Finally, the input signal is displayed using the calculated bit period as the basis for a scale.