摘要:
The invention relates to a signal generator for generating a sequence of digital values according to a reference clock signal, comprising at least one input terminal for receiving a an increment signal and an offset signal, a start value circuit adapted for determining a counter start value on the base of the offset signal and the increment signal, a counter being adapted to be set to the start value, and to change the counter position at each cycle of the reference clock signal to a new value according to the increment signal until a defined value is achieved, and an output terminal for outputting the counter values.
摘要:
The invention relates to noise signal generator, comprising a random word generator for generating a sequence of random words, each word representing an input value, a mapping unit for receiving the sequence of random words, mapping each input value to an output value of according to a probability distribution function, and providing a corresponding sequence of output values, and a digital-to-analog converter for generating a noise signal based on the output values.
摘要:
The present invention relates to a method and a corresponding system for generating a binary pulse stream (37) based on a stable clock (76), said method being characterized by the steps of: reading a sequence of pairs of values representing LOW and HIGH state duration, respectively, of consecutive pulses of said binary pulse stream (37), said pairs of values being related to said stable clock (76), providing for each value an integral multiple part and a fractional part of the cycle time of said stable clock (76), using said integral multiple part for controlling an edge forming unit (40), said edge forming unit (40) contributes said integral multiple part of the duration of the respective state of the respective pulse to said binary pulse stream (37) to be generated, and using said fractional part for controlling a delay modulation unit (42), said delay modulation unit (42) prolongs, according to said fractional part, the duration of the respective state of the respective pulse to said binary pulse stream (37) to be generated.
摘要:
A noise signal generator includes a random word generator for generating a sequence of random words, each word representing an input value, a mapping unit for receiving the sequence of random words, mapping each input value to an output value of according to a probability distribution function, and providing a corresponding sequence of output values, and a digital-to-analog converter for generating a noise signal based on the output values.
摘要:
A delay unit for providing an output signal delayed by a delay time with respect to a periodic signal received at its input, the delay unit comprises a first delay cell adapted to receive the periodic signal and to provide as output a first delayed signal corresponding to the input periodic signal but delayed by a variable first delay time. A selection unit receives the first delayed signal and a second signal derived from the periodic signal. A control unit controls the selection unit in order to select one of the first delayed signal and the second signal as the output signal of the delay unit, and further controls the first delay time of the first delay cell.
摘要:
A frequency-providing circuit is disclosed for providing an output signal at a frequency fout. The circuit comprises a frequency-generating unit, a frequency-changing circuit, and a synchronizing circuit. The frequency-generating unit receives a frequency-selecting control signal and provides a frequency output at a frequency fosc, whereby the frequency-generating unit is switchable between different frequencies substantially without a settling time. The frequency-changing circuit receives the frequency output and a frequency-changing control signal and derives the output signal therefrom, whereby the frequency fout of the output signal can be changed, with respect to the frequency fosc, in accordance with the setting of the frequency-changing control signal. The synchronizing circuit synchronizes the frequency-selecting control signal and the frequency-changing control signal.
摘要:
Determining a jitter property of a signal with a repetitive bit sequence of a plurality of bits includes setting a sample point at a first sampling position relative to a first transition within the bit pattern, assigning a set of digital values to comparison results of the digital signal with a threshold at the set sample point for a plurality of repetitions of the bit sequence, determining a distribution value on the base of the sum of the assigned digital values, shifting the sample point by a time increment, iteratively repeating determining the distribution value until the sample point has reached a second sampling position, determining from the distribution values a distribution function over the sample points, and determining the jitter property by using the distribution function.
摘要:
Testing a device under test—DUT—includes providing a test signal from the DUT to a test probe, taking from the test signal being present at the test probe analog samples at a first sampling rate, taking from the test signal being present at the test probe digital samples at a second sampling rate, providing a control signal indicative of sampling times of the analog samples, and performing an analysis of the digital samples in conjunction with the control signal.
摘要:
A signal shaping circuit for shaping a test signal to be provided to a device under test includes a first signal path with a first transmission behavior and adapted to receive an input signal, and at least one second signal path with a second transmission behavior and adapted to receive an input signal, wherein the outputs of the signal paths are connected to a signal combiner adapted to combine the output signals of the signal paths to the test signal as an output signal of the signal shaping circuit.
摘要:
A signal-analyzing unit has a sampling path and a reference path both receiving a digital test signal. The sampling path has a first comparator for comparing the test signal against a first threshold value and providing a first comparison signal, and a first sampling device receiving as input the first comparison signal and a first timing signal. The reference path has a second comparator for comparing the test signal against a second threshold value and providing a second comparison signal, and a second sampling device for receiving as input the second comparison signal and a second timing signal. An analysis unit receives and analyzes the output of the sampling and reference paths.