In a device and a method for monitoring a clock signal of a position measuring device, which is connected to sequential electronics via a data transmission channel, and the data transmission channel has a data line, via which data signals are transmittable from an interface unit of the position measuring device to an interface unit of the sequential electronics, the interface unit of the position measuring device including a pulse generation unit, by which a test pulse is able to be generated based on the time pattern of the clock signal, and is transmittable via the data line to the interface unit of the sequential electronics. The interface unit of the sequential electronics includes a pulse measuring unit, by which a pulse duration of the test pulse in the time pattern of a clock signal of the sequential electronics is measurable in a functionally reliable manner and by which a measured value representing the pulse duration is able to be output to a control unit for analysis.

Technologies for optimizing transmitter equalization include a computing device having a data port and a retimer. The retimer includes two serial data links, a clock recovery device, and a signal repeater. One serial data link of the retimer is connected to the data port. A bit-error rate test instrument (BERT) is connected to the other serial data link of the retimer and sweeps through multiple transmitter equalization settings while sending a compliance pattern. The retimer sends back the compliance pattern in a loopback mode. The BERT measures bit-error rate data, and an optimized transmitter equalization setting is determined based on the bit-error rate data. An end device may be configured with the optimized transmitter equalization setting and may be connected to the retimer instead of the BERT. The data port may be a PCI Express port or a backplane Ethernet port. Other embodiments are described and claimed.

A test instrument measures performance of a transponder without direct access to a line interface of the transponder. The test instrument learns parameters of internal signal conversion processes of the transponder and measures performance of the transponder based on the learned parameters.

A serial communication interface circuit includes a transmitter configured to convert first parallel data into first serial data and transmit the first serial data through an output port; a receiver configured to receive second serial data through an input port and convert the second serial data into second parallel data; a test controller configured to generate at least one test control signal; and an embedded external loopback circuit configured to form an external loopback path between the output port and the input port to receive the first serial data and output the second serial data according to at least one channel model in response to the at least one test control signal in a test mode.

A system includes a pseudorandom binary sequence (PRBS) generator configured to generate a first PRBS and a second PRBS and an exclusive-OR logic configured to exclusive-OR the first PRBS and the second PRBS to compute a third PRBS. The system also includes an adder, a correlator and a corrector. The adder adds the third PRBS to input data to compute summed data for transmission of the summed data across the channel. The correlator computes the exclusive-OR of the first PRBS and the second PRBS to reproduce the third PRBS and correlates output data from the channel to the reproduced third PRBS to compute a channel gain error and a channel memory error. The corrector extracts the input data from the output data from the channel using the computed channel gain and memory errors.

Systems, apparatuses, and methods for implementing asynchronous feedback training sequences are described. A transmitter transmits a training sequence indication to a receiver via a communication channel including a plurality of data lines. The training sequence indication includes a bit sequence to indicate the beginning of a training sequence. The indication includes a transition from a zero to a one at the midpoint of a supercycle of N clock cycles in length, followed by a predetermined number of ones. The training sequence indication is then followed by a test pattern. The beginning of the test pattern occurs at the end of a supercycle. The receiver determines if there are any errors in the received test pattern, and then sends feedback to the transmitter that indicates whether any errors were detected. Responsive to receiving the feedback, the transmitter alters delay settings for one or more of the data lines.

In some embodiments, a link monitoring system (LMS) is configured to obtain link status metrics and packet transmission metrics for network links forming a network channel between a first network device and a second network device. The LMS can obtain link status metrics from the first network device and the second network device and can also initiate the generation of packets on the network links to obtain the packet transmission metrics. Based on the status metrics and packet transmission metrics, the LMS can determine if the network links are malfunctioning.

A method for testing a vehicle-to-X communication module by means of a diagnostic device as well as an associated vehicle-to-X communication module and an associated diagnostic device. During a test mode messages are exchanged between the vehicle-to-X communication module and the diagnostic device, and evaluated in order to detect errors.

Systems, methods, and circuitries are provided to measure a swept error power ratio (SWEEPR) of a device under test. A method includes generating a time-variant stopband test signal having a time-variant stopband and determining an error of the device under test based on an output signal generated by the device under test in response to the time-variant stopband test signal.

A system includes a pseudorandom binary sequence (PRBS) generator configured to generate a first PRBS and a second PRBS and an exclusive-OR logic configured to exclusive-OR the first PRBS and the second PRBS to compute a third PRBS. The system also includes an adder, a correlator and a corrector. The adder adds the third PRBS to input data to compute summed data for transmission of the summed data across the channel. The correlator computes the exclusive-OR of the first PRBS and the second PRBS to reproduce the third PRBS and correlates output data from the channel to the reproduced third PRBS to compute a channel gain error and a channel memory error. The corrector extracts the input data from the output data from the channel using the computed channel gain and memory errors.