Advanced Micro Devices Corporation

Other

Jenny Liu Fischer

Peter Chow

Ching Yu

Bahadir Erimli

Jeffrey Roy Dwork

Autumn Jane Niu

Harand Gaspar

Po-Shen Lai

Gopal S Krishna

Jerry Chun-Jen Kuo

Ian Lam

Rajat Roy

Aspects for collision recovery interface support in a home phoneline networking alliance (HPNA) control chip are described. The aspects include providing transmit data path logic to receive and transmit data packets within the HPNA control chip. The transmit data path logic is consolidated to include a transmit state machine that handles interfacing the transmit data path logic to at least two separate collision recovery logic means of the HPNA control chip through a minimal number of generic interface signals.

Collision recovery interface support in a home phoneline networking alliance media access controller (HPNA MAC) operating in accordance with at least two different data rate standards

A method and system for deferring transmission of a data packet over a home network is disclosed, where the home network includes a host media access controller program and a media access controller. The method and system include transmitting a first transmit signal from the host media access controller program to the media access controller (MAC) to transmit a data packet, and asserting a transmit start signal from the MAC in response. The method and system further include receiving a carrier sense signal on the MAC indicating activity on a transmission medium, and delaying assertion of a final transmit signal when it is determined that both the transmit start signal and the carrier sense signal are active, thereby avoiding packet collisions.

Home network transmission deferral

A method and system for verifying collision detection and resolution in a home network that comprises a plurality of stations is disclosed. Each station in the network includes a host media access controller program and a media access controller, where each station may transmit a frame when a transmission channel is inactive. When a collision is detected, the station ceases transmission of the frame, and chooses a backoff level to resolve the conflict. The station increments a backoff level counter in response to receiving backoff signal from another station on the network, and decrements the backoff counter in response to successfully transmitting the frame. The backoff level counter is maintained such that it may be accessed through the host media access controller for monitoring collision resolution, thereby eliminating the need to monitor signals over the network.

Verification of collision detection and resolution in a home network

A network switch having switch ports for communication of data packets with respective computer network nodes according to CSMA/CD protocol that resets a retry counter within any one of the respective switch ports if backpressure is asserted by that port. The resetting of the retry counter within a port after assertion of backpressure affords the port a greater probability of winning collision mediation under the CSMA/CD protocol, thus more quickly relieving congestion which may occur in the network switch.

Apparatus and method for resetting a retry counter in a network switch port in response to exerting backpressure

A network switch having switch ports for communication of data packets with respective computer network nodes according to CSMA/CD protocol that resets a retry counter for counting data packet transmission attempts within any one of the respective switch ports if backpressure is asserted by that port. A retry limit value for the retry counter is selectively modified according to programmed information to ensure that the total number of retrys does not exceed a maximum total number of allowable retrys. Resetting the retry counter within a port after assertion of backpressure affords the port a greater probability of transmitting earlier under the CSMA/CD protocol, thus more quickly relieving congestion which may occur in the network switch. Selective modification of the retry limit value according to programmed information adds flexibility to vary the maximum total number of allowable retrys based upon current network switch conditions or the priority of a particular data packet.

Apparatus and method for programmably modifying a limit of a retry counter in a network switch port in response to exerting backpressure

A network switch in a packet switched network includes a plurality of network switch ports, each configured for sending and receiving data packets between a medium interface and the network switch. The network switch port includes an IEEE 802.3 compliant transmit state machine and receive state machine configured for transmitting and receiving network data to and from a medium interface, such as a reduced medium independent interface, respectively. The network switch port also includes a memory management unit configured for selectively transferring the network data between the transmit and receive state machines and a random access transmit buffer and a random access receive buffer, respectively. The memory management unit transfers the network data between the transmit and receive state machines and the respective buffers based on prescribed interface protocol signals between the memory management unit and the transmit and receive state machines. Hence, the memory management unit and the transmit and receive state machines transfer data according to a prescribed interface protocol, where a request-based protocol enables data transfers to be performed independent of different clock domains encountered within the network switch port.

Apparatus and method in a network switch port for transferring data between buffer memory and transmit and receive state machines according to a prescribed interface protocol

A network switch having switch ports for communication of data packets with respective computer network nodes according to CSMA/CD protocol that resets a retry counter for counting data packet transmission attempts within any one of the respective switch ports if backpressure is asserted by that port. A retry limit value for the retry counter is modified to ensure that the total number of retrys does not exceed a maximum total number of allowable retrys. The resetting of the retry counter within a port after assertion of backpressure affords the port a greater probability of transmitting earlier under the CSMA/CD protocol, thus more quickly relieving congestion which may occur in the network switch. The modification of the retry limit value ensures that the number of retrys for the port does not exceed industry standards.

Apparatus and method for modifying a limit of a retry counter in a network switch port in response to exerting backpressure

A network switch in a packet switched network includes a plurality of network switch ports, each configured for sending and receiving data packets between a medium interface and the network switch. The network switch port includes an IEEE 802.3 compliant transmit state machine and receive state machine configured for transmitting and receiving network data to and from a medium interface, such as a reduced medium independent interface, respectively. The network switch port also includes a memory management unit configured for selectively transferring the network data between the transmit and receive state machines and a random access transmit buffer and a random access receive buffer, respectively. The transmit state machine outputs a flush transmit buffer signal to the transmit memory management unit in response to a detected error in transmitting the transmit data. The transmit memory management unit, in response to the flush transmit buffer signal, sets an incremented transmit buffer pointer value to a buffer pointer value corresponding to a next transmit data stored in the transmit buffer.

Architecture and method for flushing non-transmitted portions of a data frame from a transmitted FIFO buffer

A system for adjusting late collision slot time is provided in a network interface having a media access control (MAC) engine that performs collision detection. The MAC engine comprises a MAC transmit block that transmits frames via a media independent interface (MII) to an ektemal physical layer device (PHY) coupled to the MII, and a MAC receive block for receiving frames from the PHY. A MAC control register is configured for storing ablate collision time slot adjustment value used to adjust the late collision slot time. The late collision time slot adjustment value is programmed to compensate for variations in internal delays of PHYs that may be connected to the MII.

System and method for programming late collision slot time

A data structure to provide high performance in the transmit portion of an ethernet controller. The data structure includes the data to be transmitted, the STATUS information of the data to be transmitted, and the DESCRIPTOR information of the data to be transmitted. The data is organized in 8-bit bytes in 32-bit rows, the 32 bit STATUS information is organized in four 8-bit bytes in a 32 bit row, and the 32 bit DESCRIPTOR information is organized in four 8-bit bytes in a 32 bit row. A one-bit tag field is associated with each of the rows and a 1 in the tag field indicates that the end-of-packet is located in the row associated with that tag. The lower four bits of a STATUS byte contains information indicating which byte in the row contains the end-of-packet.

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Mountain View, CA, United States of America

Jenny Liu Fischer