National Semiconductor Corporation

Texas Instruments Corporation

David Rosselot

Vijaya G Ceekala

Xin Liu

Benjamin Clyde Buchanan

Andrew McLean

In described examples, a receiver includes a receiver input adapted to receive input data. A selector is coupled to an output of the receiver and is configured to generate a destination indication at an output of the selector. A switch is coupled to the receiver input. The switch is adapted to generate a first transmission at a switch local output in response to an indication of the selector output and the input data. The switch is further adapted to generate a second transmission at a switch system output in response to the input data. The switch local output is adapted to be coupled to a first destination node, and the switch system output is adapted to be coupled to a second destination node.

Selected forwarding between serially chained devices

A multi-port Ethernet Physical (PHY) layer device includes multiplexed datapaths and control logic such that each transmit data connection for a port may be mapped to any combination of the transmit data connections for one of multiple Media Access Control (MAC) layers, and each received data connection for a port may independently be mapped to an combination of the receive data connections for one of the MAC layers and the transmit data connection(s) for the other port(s). The device may be configured to operate in normal and port swap modes, to support failover switching and/or dedicated redundant connections, as a cable extender or media converter, as a snoop device, to form an Ethernet ring topology, for broadcast transmit or mirrored receive, or as a unidirectional repeater.

Independently configurable port redirection in a multi-port ethernet physical layer

A system and method is disclosed for monitoring the quality of a data link in a 100 Mb Ethernet physical layer device. A link quality monitor detects operational values of data link parameters such as digital equalizer C1 coefficient, digital adaptive gain control, digital base line wander, recovered clock long-term frequency offset, and recovered clock frequency control. When an operational value of a data link parameter exceeds a high or low threshold value, the link quality monitor sends a drop link signal to cause the current data link to be dropped and a new data link established.

System and method for providing a link quality monitor for a 100Mb ethernet physical layer device

A system and method for minimizing transmit latency uncertainty in a 100 Mb RMII Ethernet physical layer device is disclosed. A 100 Mb RMII Ethernet transmit physical layer device comprises a divide circuit that selects a phase of a transmit clock signal for transmitting data. The invention comprises a reset circuit that aligns the divide circuit to select an optimal phase of the transmit clock signal for transmitting data. The reset circuit of the invention is capable of reducing the transmit latency uncertainty from approximately twenty nanoseconds to four nanoseconds.

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Atlanta, GA, United States of America

David Rosselot