摘要:
A cable testing system that tests cable includes a pulse generation module that transmits a first pulse on a first communications channel of the cable. A sampling module waits a predetermined time period after the pulse generation module transmits the first pulse and then detects a first amplitude of a reflected signal on a second communications channel of the cable. A time domain reflection (TDR) module receives the first amplitude and verifies proper operation of the cable based on the first amplitude. The predetermined time period corresponds with an estimated roundtrip propagation delay of the first pulse when the first pulse is reflected back to the cable testing system after traveling a first predetermined distance along the cable. The sampling module incrementally increases the predetermined time period during subsequent iterations of a cable test in order to verify proper operation of a predetermined segment of the cable.
摘要:
A physical layer device for a network interface includes a reconciliation device that includes a first interface that outputs data. A physical coding sublayer (PCS) device communicates with the first interface and includes an encoder that encodes the data to produce an encoded data block including an offset portion and n data blocks, each including at least one of data portions and control code portions. The encoder is capable of locating the control code portions within any of the n data blocks based on the offset portion.
摘要:
A network media selection system comprises a memory that stores priority information for each of a plurality of ports and a media selector module that communicates with the memory, that receives activity signals and link signals from the plurality of ports, and that uses the activity signals, the link signals, and the priority information to generate enable signals for the plurality of ports. A respective port attempts to establish a link when a corresponding one of the enable signals is in a first state, and the respective port detects physical layer activity when a corresponding one of the enable signals is in a second state. The media selector module selectively sets enable signals to the second state for all of the plurality of ports other than a target port, which has the highest priority and has generated a link signal.
摘要:
An apparatus and method for laser probing of a DUT at very high temporal resolution is disclosed. The system includes a CW laser source, a beam optics designed to point two orthogonally polarized beams at the same location on the DUT, optical detectors for detecting the reflected beams, collection electronics, and an oscilloscope. The beam optics defines a common-path polarization differential probing (PDP) optics. The common-path PDP optics divides the laser beam into two beams of orthogonal polarization. Due to the intrinsic asymmetry of a CMOS transistor, the interaction of the beams with the DUT result in different phase modulation in each beam. This difference can be investigated to study the response of the DUT to the stimulus signal.
摘要:
A network comprising a first network device including a first physical layer device with a receiver and a first autonegotiation circuit having an ability detect state and including a bypass timer that determines a predetermined period, a first medium, and a second network device that includes a second physical layer device and that communicates over the first medium with the first network device. The first network device enables autonegotiation bypass and establishes a link with the second network device after the predetermined period during which a link between the first and second network devices is not up, and the receiver of the first physical layer device is in sync.
摘要:
A network device includes a media access control (MAC) device that transmits a first data stream at a first data rate that includes symbols having M bits. A translator converts the first data stream to a second data stream at a second data rate. The translator includes a data appender that appends N bits to the symbols in the first data stream to generate second symbols having M+N bits. A data duplicator duplicates the second symbols X times to produce the second data stream at the second data rate.
摘要:
A physical layer device for a network device comprises a converter module that selectively converts an n-bit input to an m-bit output based on first and second mapping functions. A scrambler module selectively scrambles the m-bit output. An encoding module receives the m-bit output from the scrambler module and selectively maps the m-bit output based on the first mapping function to X level output signals and the m-bit output based on the second mapping function to Y level output signals, where X and Y are integers greater than one and X is different than Y.
摘要:
A system, apparatus, and method for analyzing photon emission data to discriminate between photons emitted by transistors and photons emitted by background sources. The analysis involves spatial and/or temporal correlation of photon emissions. After correlation, the analysis may further involve obtaining a likelihood that the correlated photons were emitted by a transistor. After correlation, the analysis may also further involve assigning a weight to individual photon emissions as a function of the correlation. The weight, in some instances, reflecting a likelihood that the photons were emitted by a transistor. The analysis may further involve automatically identifying transistors in a photon emission image.
摘要:
A physical layer device including a first port and a second port comprises a cable tester that communicates with the first and second ports and that determines a cable status, which includes an open status, a short status, and a normal status. Opposite ends of a cable selectively communicate with the first and second ports. The cable tester includes a test module that transmits a test pulse on the cable, measures reflection amplitude, calculates a cable length, and determines the cable status based on the measured amplitude and the calculated cable length. A frequency synthesizer communicates with the cable and that selectively outputs a plurality of signals at a plurality of frequencies on the first port. An insertion loss calculator receives the signals on the second port and that estimates insertion loss.
摘要:
A physical layer device communicates with a second physical layer device over a cable. The physical layer device includes a cable tester that identifies when the second physical layer device is disconnected from the cable. The cable tester includes a test initiating circuit that initiates a cable test when a link is lost, a test module that transmits test pulses on the pairs of the cable, measures reflection amplitudes, calculates cable lengths, and determines whether the pairs have said open status based on said measured amplitude and said calculated cable length, and a reporting circuit that generates a disconnect signal when at least one of the pairs has an open status.