Abstract: A testing system includes a signal generator circuit, a jitter modulation circuit, and an oscilloscope circuit. The signal generator circuit is configured to generate a clock pattern signal with a single clock pattern frequency. The jitter modulation circuit is configured to generate a jitter signal. A device-under-test is configured to receive an input signal. The input signal is a combination signal of the clock pattern signal and the jitter signal. The device-under-test includes a clock data recovery circuit and is further configured to generate an output signal according to the input signal. The oscilloscope circuit is configured to receive the output signal for determining performance of the clock data recovery circuit.

Abstract: A testing system includes a signal generator circuit, a jitter modulation circuit, and an oscilloscope circuit. The signal generator circuit is configured to generate a clock pattern signal with a single clock pattern frequency. The jitter modulation circuit is configured to generate a jitter signal. A device-under-test is configured to receive an input signal. The input signal is a combination signal of the clock pattern signal and the jitter signal. The device-under-test includes a clock data recovery circuit and is further configured to generate an output signal according to the input signal. The oscilloscope circuit is configured to receive the output signal for determining performance of the clock data recovery circuit.

Abstract: A headset test device includes a supporting frame, a drive adjusting system, a head model mechanism and a sensing system. The supporting frame includes a transverse adjusting supporter assembly and a vertical adjusting supporter assembly. The drive adjusting system includes a first motor and a second motor. The transverse adjusting supporter assembly and the vertical adjusting supporter assembly are connected with and are driven by the first motor and the second motor, respectively. The head model mechanism includes a parietal region driven by the second motor to vertically move, and two aural regions driven by the first motor to move close to or away from each other for increasing or reducing a distance between the two aural regions. Each of the two aural regions is equipped with an artificial ear. The sensing system includes a force sensing unit, a pressure sensing unit and a temperature sensing unit.

Abstract: A method for operating a network device is provided. The method comprises steps of providing a first transceiver to establish a first link via a first medium; providing a second transceiver to establish a second link via a second medium; and enabling one of the first and the second transceivers to establish a corresponding one of the first and second links according to a predetermined order, wherein a media access controller transmits a first datum via the first medium by using the first link, and transmits a second datum via the second medium by using the second link.