Abstract: Embodiments of the present invention provide a variable inter symbol interference generator that generates a data signal having a variable amount of inter symbol interference by passing a data signal through (1) a programmable filter having an adjustable frequency response, and through (2) a fixed filter having a fixed frequency response such as a PCB trace, a length of cable, a discrete filter, or the like. By adjusting the parameters and therefore the insertion gain or loss of the programmable filter, and combining this with one or more fixed filters, a large range of continuously variable and finely tunable inter symbol interference amounts can be easily generated.

Abstract: Embodiments of the present invention provide a variable inter symbol interference generator that generates a data signal having a variable amount of inter symbol interference by passing a data signal through (1) a programmable filter having an adjustable frequency response, and through (2) a fixed filter having a fixed frequency response such as a PCB trace, a length of cable, a discrete filter, or the like. By adjusting the parameters and therefore the insertion gain or loss of the programmable filter, and combining this with one or more fixed filters, a large range of continuously variable and finely tunable inter symbol interference amounts can be easily generated.

Abstract: Disclosed herein is a method and apparatus used to measure the number of time a multi-valued data signal transmitted from either a communication device of subsystem deviates across and into one or more bounded areas or zones as defined by an eye mask that is overlaid onto an eye diagram. The present invention employs an iterative process to accumulate and display mask violation that might result from a data signal transmitted from a target device or communications subsystem that deviates across the boundaries either above or below or into the center of the eye diagram. In addition, the present invention also has the ability to isolate particular threshold voltage-delay points along the boundaries above or below and around the perimeter of the mask polygon of the eye diagram where mask violations have occurred. This provides the ability to supply additional information and feedback about the behavior and performance of the targeted device or subsystem being tested.

Abstract: A measurement device includes a measurement circuit that generates a parametric measurement data signal including parametric characteristics of an input signal. In an exemplary embodiment, the parametric characteristics are measured at predetermined increments of time. A population limit analyzer is coupled to the measurement circuit and generates limit data in response to the parametric measurement data signal. A measurement limit checker is coupled to the population limit analyzer and generates a signal indicating that the characteristics of the parametric measurement data signal is within acceptable limits. With this information, the user is able to quickly grade a selected device under test (DUT). A device performance measurement method includes receiving an input signal. Next, statistical characteristics are determined from the parametric measurements of the input signal. Performance limits are extrapolated from the statistical characteristics of the parametric measurements.

Abstract: Disclosed herein is a method and apparatus used to measure the number of time a multi-valued data signal transmitted from either a communication device of subsystem deviates across and into one or more bounded areas or zones as defined by an eye mask that is overlaid onto an eye diagram. The present invention employs an iterative process to accumulate and display mask violation that might result from a data signal transmitted from a target device or communications subsystem that deviates across the boundaries either above or below or into the center of the eye diagram. In addition, the present invention also has the ability to isolate particular threshold voltage-delay points along the boundaries above or below and around the perimeter of the mask polygon of the eye diagram where mask violations have occurred. This provides the ability to supply additional information and feedback about the behavior and performance of the targeted device or subsystem being tested.

Abstract: Disclosed herein is an apparatus for testing a digital device. The apparatus includes a generator adapted for connection to the device under test for generating a controlled data stream in words. The generator transmits the controlled data stream to the device which in turn transmits the controlled data stream to a detector. The detector is adapted for connection to the device and receives the controlled data stream. The detector compares the controlled data stream to an expected result and identifies each unexpected result as an error event. The apparatus includes a computer which records the location information of each error event and performs statistical and distribution analysis to allow a user to obtain through high resolution graphical display information used to diagnose the performance of the tested device. The computer controls the input and output of data from the device under test.