摘要:
A physical layer of a first network device is connected to cable of an Ethernet network. A digital signal processor (DSP) is connected to the cable. The DSP receives and decodes first signals on the cable from a second device. The DSP codes and transmits second signals to the second device on the cable. An autonegotiation controller is connected to the DSP and includes a cable detector that determines a first number of pairs of twisted pair wires of the cable that are operable. The autonegotiation controller also includes a speed adjuster that masks an advertised speed of the first device when the cable detector determines that the first number is less than the number required for a requested speed of the first device.
摘要:
A rate adaptation layer (RAL) module for converting from a first interface operating at a first rate to a second interface operating at a second rate comprises first and second input/output (I/O) modules that communicate with the first and second interfaces, respectively. A repeater module receives symbols from the first I/O module, and transmits the symbols n times to the second I/O module, where n is determined by the first and second rates. A pull-down module receives symbols from the second I/O module and selectively extracts symbols to be communicated to the first I/O module.
摘要:
A device for controlling interpacket gaps in a data stream of packets. A receiver to receive the data stream of packets. A controller to monitor the data stream of packets and to selectively delete interpacket gaps. A transmit buffer to buffer packet data in the data stream of packets flowing from the controller.
摘要:
A physical layer device comprises a mode selector that selects a mode. A clock selects a clock frequency from T clock frequencies based on the mode. A converter module selects one of N mapping functions based on the mode and converts an n-bit input to an m-bit output based on the selected one of the N mapping functions. A scrambler module scrambles the m-bit output or passes the m-bit output unchanged based on the mode. An encoding module modulates the m-bit output based on the selected clock frequency and one of M modulation modes selected based on the mode, where T, n, m, N and M are integers greater than one and n is not equal to m.
摘要:
A network device includes a media access controller (MAC) and a physical layer device including an interface that communicates with the MAC, and first and second transceivers. A first autonegotiation circuit attempts to establish a first link using the first transceiver over a first medium. A second autonegotiation circuit attempts to establish a second link using the second transceiver over a second medium. A media selector communicates with the interface and the first and second autonegotiation circuits and enables data flow from the first medium to the MAC using the interface when the link over the first medium is established first. When a preferred medium selector prefers the second medium, the media selector monitors the second medium for a qualified energy detect event. When the qualified energy detect event occurs, the media selector allows a link to be established by the second medium.
摘要:
A physical layer of an Ethernet network device includes first, second, third and fourth terminals. An autonegotiation circuit includes an autonegotiation wait timer having an autonegotiation wait period. An auto-crossover circuit selectively configures the first and second terminals as one of a transmitter and a receiver and the third and fourth terminals as the other of the transmitter and receiver. The auto-crossover circuit includes a sample timer having a sample timer period that has a value that is greater than or equal to the autonegotiation wait period. The auto-crossover circuit includes a random number generator that communicates with the sample timer and generates n random numbers. The sample timer selects one of n sample timer periods based on the generated random number. The n sample timer periods have values that are greater than or equal to the autonegotiation wait period.
摘要:
A physical coding sublayer (PCS) device in a physical layer device of an Ethernet network device includes a multiplexer that aggregates data, which includes at least one of data portions and control portions, from a plurality of data streams into a multiplexed data block. An encoder encodes the multiplexed data block to produce an encoded data block that includes n data blocks. Each of the n data blocks includes at least one of data portions, pointer portions, and control code portions. The control code portions can be located within any of the n data blocks.
摘要:
A cable tester comprises a test initiating module that performs B cable tests. Each of said B cable tests includes selectively transmitting a test pulse on the cable, measuring a reflection amplitude, and calculating a cable length. A test results module determines a cable status for each of said B cable tests based on said measured amplitude and said calculated cable length and that determines an overall cable status of the cable based on the cable at least one of passing and failing A out of B cable tests. A and B are integers greater than zero and B is greater than A.
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 three level output signals and the m-bit output based on the second mapping function to four level output signals.
摘要:
A system for encoding signals for a network device includes an encoder configured to encode a transmit control signal. The transmit control signal includes a transmit enable signal in a first half of a cycle of a clock signal, and a transmit error signal in a second half of the cycle of the clock signal. The system includes a control signal transmitter configured to transmit the encoded transmit control signal. The system includes a data signal transmitter configured to transmit a transmit data signal. When neither the transmit enable signal nor the transmit error signal is in a first state in a respective half of the cycle of the clock signal, the transmit data signal includes signaling data.