摘要:
A Packet communication system has a first line interface; a second line interface that accommodates lines slower than lines accommodated by the first line interface; a crossbar switch; and a scheduler that periodically receives packet output requests from the first and second line interfaces and sends grants based on the requests for the crossbar switch to the first and second line interfaces. The link capacity between the first line interface and the crossbar switch is made higher than that between the second line interface and the crossbar switch, whereby a packet communication system capable of accommodating line interfaces with different speeds efficiently can be provided.
摘要:
A packet switching system arbitrates between Virtual Output Queues (VoQ) in plural input buffers, so as to grant the right of transmitting data to a crossbar switch to some of the VoQs by taking both an output data interval of a VoQ and the queue length of a VoQ as parameters. The system suppresses the delay time of the segment of a VoQ having a high load, thereby preventing buffers from overflowing; and, also, the system permits a VoQ having a low load to transmit segments under no influence of the VoQ that has a high load and is just reading out the segment.
摘要:
A packet switch has a switch section formed by a plurality of crossbar switch planes and plurality of interfaces, and each interface outputs in parallel input packets in block units to the plurality of crossbar switch planes in response to signals from a scheduler, wherein when n crossbar switch planes can be mounted on the packet switch, each interface allocates time slots corresponding to the n crossbar switch planes or when a switch plane is additionally mounted, a block is read at a time slot corresponding to the additional switch plane or when a switch plane is stopped from working, an idle time slot is used to prevent a block from being output to the switch plane which is unused.
摘要:
In a method for data transmission, which transmits data through a transmission line, which integrates a plurality of links into one transmission line, a first link group, which transmits information data by at least one link out of a plurality of links, a second link group, which transmits parity data generated by the information data by at least one link out of a plurality of links, which are different from the first link group, and a third link group, which generates an error check data related to an error correction from the information data or the parity data, when an error occurs in the information data or the parity data, and transmits by at least one link out of a plurality of links, which are different from the first link group and the second link group, are integrated and transmitted.
摘要:
In pulse width control equalization, attention is paid to the existence of the symmetry of anteroposterior signals and thereby the size of a table in which the adjustment amount of an edge position is stored is reduced to the power of one-half. Pattern jitters caused by inter-symbol interference are suppressed. The pulse time span of each symbol is adjusted to an optimum pulse width determined by a calculating formula or search in a table in response to a code sequence to be transmitted. In the configuration wherein a table is used, the table to store an edge position adjustment amount wherein the row of the exclusive OR of two symbols located at positions symmetrical to each other before and after a center symbol now ready to be sent in the code sequence is used as a search key is made.
摘要:
Digital signals having respective pieces of frequency information different from each other are bundled, and transmitted at high speed. On receiving side, digital signals retaining the respective pieces of frequency information are recovered and separated. Transmitter apparatus divides pieces of transmission data that have the different pieces of frequency information and correspond to respective input channels into data blocks having a fixed length, as valid data, and subsequently multiplexes the data blocks corresponding to the respective input channels and outputs the multiplexed data to a transmission path. A receiver apparatus divides data string received into data flows and subsequently restores the transmission data, from the data blocks consecutive in each data flow and stores the restored data, and outputs transmission data corresponding to the respective data flows in synchronization with clocks generated for these data flows.
摘要:
It is provided a data transmission system comprising a transmitter, a repeater and a receiver. The transmitter and the repeater are coupled through a first transmission path and the receiver and the repeater are coupled through a second transmission path. The transmitter, the repeater and the receiver have virtual lanes. The transmitter demultiplexes the transmission data into as many data streams as a number of useable virtual lanes based on useable lane information. The repeater monitors failures of the transmission lanes of the first transmission path and the virtual lanes. The receiver monitors failures of the transmission lanes of the second transmission path and the virtual lanes, selects the useable virtual lanes, sends to the transmitter the useable lane information, corrects a wrong order of the received data streams and a shift of reception point in the virtual lanes, and restores the demultiplexed data streams into the transmission data.
摘要:
A transmitter communicates with a receiver and an error corrector corrects bit errors generated during data transmission. The transmitter has a scrambler unit that scrambles data so that a running disparity of 0 and 1 in the input data is substantially zero. A bit-string converting unit 15 that adds bit data for ensuring a maximum run length of a serial bit string of the scrambled data and converts control information to bit data of a fixed value. A synchronization timing generating unit 16 divides the transmitted data by a constant interval and converts the transmission data to a data block. A bit-string converting unit extracts a fixed-value bit pattern of the control data from the bit string of the data block, converts the bit pattern to the control information, and discriminates the data and the control information. A descrambler unit reconverts the data-scrambled data to the data before scrambling.
摘要:
Provided is a transversal filter, in which delayers and multipliers are connected in series, includes: a first multiplier for multiplying a first tap coefficient set by a tap coefficient register module and an input signal to output a result of multiplication; a first delayer for delaying the value output from the first multiplier by a predetermined time to output the delayed value; a second multiplier for multiplying a second tap coefficient set by the tap coefficient register module and an input signal to output a result of multiplication; a first adder for adding the value output from the delayer situated upstream to the value output from the second multiplier to output a result of addition; a second delayer for delaying the value output from the first adder by a predetermined time to output the delayed value; and a selector for selecting one of the input signal, the value output from the first delayer, and the value output from the second delayer to output the selected one.
摘要:
A transmitting and receiving technique in which a load on data signal lines is reduced while maintaining a communication quality, thereby making it possible to improve the throughput of data channels. In a transceiver, a transmitter side has an encoder circuit that transmits a bit sequence obtained by encoding link information to a clock signal line, and a receiver side has a clock and data recovery circuit 17 that extracts a clock component from a signal received from the clock signal line, a decoder circuit 19 that decodes the extracted signal to reproduce the link information, and a bit deskew circuit 21 that adjusts a skew that is lower than one bit on the basis of a clock component.