Abstract: A programmable delay circuit is provided in either data input path or a clock input path of a sequential element contained in a scan chain of an integrated circuit. The scan chain is used to test the integrated circuit using a sequential scan technique (e.g., Automatic test pattern generation (ATPG)). Due to the programmability of delay magnitude, the burden on a designer to achieve synchronization of the data input with the clock signal while testing, is reduced.

Abstract: A network device identifies priority level information for data frames it receives. The network device includes input ports, a memory, an action generator, and a port vector queue. The input ports receive the data frames. Each of the received data frames specifies one or more classes of service. The memory stores priority level information corresponding to each of the classes of service. The action generator generates an action tag for each of the received data frames. The port vector queue uses the action tag from the action generator for each of the received data frames to access the memory to identify the priority level information associated with the received data frame.

Abstract: A network device includes a group of queues, each having a weighted round robin mechanism. The priority queues on a port detect an overflow condition and transfer a flag to the weighted round robin device in response to detecting the overflow condition. The weighted round robin mechanism adjusts the weight associated with one or more of the priority queues in response to receiving the flag and transfers data from the queues based on the adjusted weights.

Abstract: A host channel adapter configured for outputting packets, according to a service protocol requiring acknowledgement messages within a prescribed time interval following transmission, utilizes a retransmission table for storing entries identifying the packets awaiting respective acknowledgment messages during the respective prescribed time intervals. A retransmission manager is configured for updating the retransmission table after each access cycle, defined as a prescribed number of clock cycles. The retransmission manager also identifies a number of transmitted packets within the corresponding access cycle within a selected initial entry for the access cycle. An acknowledgment manager in the receive portion of the host channel adapter resets to zero an acknowledgment waiting bit in a selected entry in response to an acknowledgment message identifying the corresponding packet.

Abstract: A network device determines forwarding information for received data frames. The network device includes input ports, queuing logic, a forwarding engine, and a port filter. The input ports receive data frames. The queuing logic transfers at least some of the received data frames to an external memory. The forwarding engine generates forwarding information for at least some of the data frames transferred by the queuing logic to the external memory. The port filter stores forwarding information for one or more of the received data frames and analyzes each of the received data frames to determine whether there is stored forwarding information related to the received data frame. When there is stored forwarding information related to the received data frame, the port filter uses the stored forwarding information to forward the received data frame.

Abstract: A system automatically establishes a trunk between first and second network devices. The system monitors a source address and destination addresses in packets destined to or received from the second network device and determines whether a communication pattern exists. When a communication pattern is determined to exist, the system automatically establishes the trunk between the first network device and second network device.

Abstract: A router is configured for sending and receiving data packets on an InfiniBand™ network. When placed between an Ethernet network and an InfiniBand™ network, the router is configured to receive an Ethernet data packet having a VLAN tag indicative of layer 2 priority data of the Ethernet packet. The router includes a mapping table having multiple entries, each entry specifying a VLAN tag and a corresponding service level. A controller is configured for parsing the VLAN tag and determining the service level for the VLAN tag. The controller outputs the Ethernet packet on the InfiniBand™ network within an InfiniBand™ packet according to the determined service level.

Abstract: A network device includes a port filter, a first logic device, and a second logic device. The port filter receives a data frame and generates first data relating to the data frame. The first logic device generates second data for the received data frame. The second logic device receives the first data and the second data, determines whether the first data contains a valid first priority value, and assigns the valid first priority value to the data frame when the first data contains the valid first priority value. When the first data does not contain a valid first priority value, the second logic device determines whether the second data contains a valid second priority value, and assigns the valid second priority value to the data frame when the second data contains the valid second priority value.

Abstract: A network device includes a filter and an embedded processor. The filter receives a packet, determines whether the packet is an RSVP packet, and transmits an interrupt signal when the packet is an RSVP packet. The embedded processor receives the interrupt signal and generates at least one packet processing parameter in response to the interrupt signal.

Abstract: A network interface includes a network medium interface operatively coupled to a software device driver arrangement, with a legacy media access controller (MAC) therebetween. The device driver arrangement includes a legacy MAC device driver configured to communicate with the legacy MAC, and an intermediate driver configured to communicate with the network medium interface. The intermediate driver and the network medium interface may communicate with one another by use of special frames, for example to send and receive control information. The special frames are formatted to pass through the legacy MAC, and include an identifier so that they can be identified at the intended destination, either the intermediate driver or the network medium interface. Upon identification, the control information is extracted at the destination. The network medium interface may include one or more MACs as well as one or more physical layer devices (PHYs).

Abstract: A router is configured for sending and receiving data packets on an InfiniBand™ network. The router is configured to receive a network layer data packet having a transport header having an application identifier indicative of application layer priority data of the network layer packet. The router includes a mapping table having multiple entries, each entry specifying an application identifier and a corresponding service level. A controller is configured for parsing the transport header and determining the service level for the application identifier. The controller outputs the network layer packet on the InfiniBand™ network within an InfiniBand™ packet according to the determined service level.

Abstract: A multiport network device includes output port logic, priority logic, a memory, and memory logic. The output port logic generates output port data that identifies output ports to transmit received packets. The priority logic generates priority data that identifies priorities of the received packets. The memory stores the output port data from the output port logic and the priority data from the priority logic. The memory logic receives priority data relating to one of the received packets from the output port logic, determines whether the memory stores output port data relating to the packet, ignores the received priority data when the memory stores no output port data relating to the packet, and when the memory stores output port data relating to the packet, transmits the received priority data and the stored output port data to the identified output port.

Abstract: A network device that controls the communication of data frames between stations includes a number of receive ports that receive data frames from the stations and a number of output ports that transmit the data frames to their intended destinations. The network device also includes a number of output queues that store data forwarding information associated with the received data frames. The network device partitions each of the output queues into a number of portions corresponding to the priorities supported by the network device. The number of portions and the size of each portion of the output queues may be programmable by the user.

Abstract: A network device determines priority of a packet based on the priority of one or more previously-received packets. The network device includes a memory, a forwarding engine, and a processor. The memory stores priority information for one or more previously-received packets. The forwarding engine generates the priority information stored in the memory. The processor determines whether to apply the priority information stored in the memory to a received packet. When the priority information applies to the received packet, the processor sends the priority information to the forwarding engine. In response to the priority information, the forwarding engine bypasses the generation of priority information for the received packet and thus cuts down on processing time in the switch and, by doing so, reduces the end-to-end latency for the packet in the network.

Abstract: A method of testing a network physical layer device (PHY) having a media independent interface (MII) includes sending information between the PHY and a tester along the data buses of the MII. The information may be sent in the form of special frames, the special frames being sent from the tester to the PHY including an identifier. The PHY includes means for detecting the identifier, for extracting control information from the special frames, and for using the control information to execute write operations to and read operations accessing the memory registers of the PHY, and for sending information to the tester. The information may be passed between the PHY at an exemplary rate of 100 Mb/sec.

Abstract: A network node has multiple physical layer devices (PHYs), multiple media access controllers (MACs), and means for gathering information regarding the capabilities of other nodes on the network. The node capability information may be gathered using hardware or software, and may involve gathering information from data frames received by the node, and/or from capability and status announcement frames received by the node. The node capability information gathered and the node topology determined may be utilized in selecting one of the MACs as an active MAC for monitoring a network medium, and/or in selecting one of the PHYs as an active PHY for transmission of frames onto the network medium. The PHYs of the interface in an exemplary embodiment are able to transmit and receive data frames or packets which are in accordance with different home phoneline networking alliance (HPNA) specifications, for example, HPNA 1.0 and HPNA 2.0.

Abstract: A system and method are provided in a media access controller for communicating to a number of physical layer devices. The system includes a common bus port for electrical coupling to a common bus that is electrically coupled to each one of the physical layer devices in communication with the media access controller. The system also includes logical circuitry to transmit a training sequence from the common bus port to the physical layer devices. Finally, the system includes logical circuitry to transmit a data block from the common bus port to a respective one of the physical layer devices by way of the common bus, the data block being transmitted in one of a number of time slots of a time division multiplexed transmission. A system and method are also provided in the physical layer devices to receive data from the media access controller.

Abstract: A system shapes traffic in a multiport network device. The system includes multiple token buckets and token bucket logic. The token buckets correspond to multiple priority queues of the multiple output ports of the network device and store one or more tokens. Each of the tokens corresponds to a byte of one or more received packets to be transmitted by the network device. The token bucket control logic generates the tokens for the token buckets. The token bucket control logic includes a master counter and multiple bucket counters. The master counter counts to a first count value and generates a done signal when the count reaches the first count value. The bucket counters, corresponding to the token buckets, receive the done signal, count to a second count value, and generate a token increment signal for storing a token in the corresponding token buckets when the count reaches the second count value.

Abstract: A network device includes a port filter, a first logic device, and a second logic device. The port filter receives a data frame and generates first data relating to the data frame. The first logic device generates second data for the received data frame. The second logic device receives the first data and determines whether the second data has been received. When the second data has not been received, the second logic prevents a transfer of different first data relating to a different data frame from the port filter.

Abstract: A system controls transmission of packet flows in a network device on a per-flow basis. The system includes multiple token buckets corresponding to the output ports of the network device, multiple bucket counters associated with the token buckets, and control logic. The token buckets store one or more tokens. Each of the tokens corresponds to a portion of one or more received packet flows to be transmitted by the network device. The bucket counters have one or more programmable counting properties and generate token increment signals for storing tokens in corresponding ones of the token buckets. The control logic monitors the packet flows being sent through the network device and controls the programmable counting properties of the bucket counters based on the monitored packet flows.