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: 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.