Measurement system having a digital edge trigger detection circuit that is capable of operating at the full signal bandwidth of the measurement system

A measurement system comprising:

• N time-interleaved analog-to-digital converters (ADCs), the ADCs sampling a time-varying waveform at instants in time that are offset from one another in time to produce N respective digital data sets that are time-interleaved, each digital data set comprising digital data samples, and wherein N is a positive integer that is equal to or greater than 2;
• and
• N processors, each processor being interconnected with a respective ADC to receive a respective digital data set from the respective ADC, the processors being connected in a daisy chain configuration such that each processor communicates with at least one adjacent processor in the daisy chain configuration, and wherein each processor performs an edge trigger detection algorithm that processes the respective digital data set to determine whether a respective early sample in time that is below a lower threshold value, THL, exists, to determine whether a respective late sample in time that is below THL or above a higher threshold value, THH, exists, and to determine whether a respective early sample in time that is above THH exists, the processors sharing information, via the daisy chain configuration, regarding any early samples in time below THL, any late samples in time below THL or above THH, and any early samples in time above THH to determine which early sample in time below THL, if any exists, is the earliest sample in time below THL, which late sample in time below THL or above THH, if any exists, is the latest sample in time below THL or above THH, and which early sample in time above THH, if any exists, is the earliest sample in time above THH, and wherein at least one of the processors acts as a master processor that uses the earliest sample in time below THL, the latest sample in time below THL or above THH, and the earliest sample in time above THH that was later than the earliest sample in time below THL to determine whether a trigger threshold level crossing has been detected.

A method for detecting edge triggers in a measurement system, the method comprising:

• in a plurality of processors that receive time-interleaved samples output from respective time-interleaved analog-to-digital converters (ADCs), cooperating with one another to perform a first-pass process of an edge trigger detection algorithm, wherein the first-pass process comprises:
• determining whether an earliest sample in time exists in each of a plurality of time slots that is below a lower threshold level, THL, and if so, identifying the earliest samples,
• determining whether a latest sample in time exists in each of the time slots that is below THL or above a higher threshold level, THH, and if so, identifying the latest samples, and
• generating an indication that indicates whether the latest sample in time is below THL or is above THH;
• and
• in the plurality of processors, cooperating with one another to perform a second-pass process of the edge detection algorithm, wherein the second-pass process comprises:
• for each time slot, if said indication indicates that the latest sample in time from the previous time slot is below THL, detecting a trigger threshold level crossing by determining whether an earliest sample in time exists in the current time slot that is above THH, and
• for each time slot, if said indication indicates that the latest sample in time from the previous time slot is above THH, detecting a trigger threshold level crossing by determining whether an earliest sample in time exists in the current time slot that is above THH and is later in time than the earliest sample in time in the current time slot that is below THL.