Hewlett-Packard Company

Eric McLaughlin

Mark C Lucas

Christian J Warling

Mohammed Bustany

A network node includes a serial physical sublayer (PHY) chip, a parallel PHY chip, and a media access control (MAC) chip. The serial physical sublayer chip, includes a single bit transmit data input, a single bit receive data output, and serial PHY control signal input/output (I/O) lines. The parallel PHY chip includes a multi-bit transmit data input, a multi-bit receive data output, and parallel PHY control signal I/O lines. The MAC chip includes a multi-bit transmit data output, a multi-bit receive data input and parallel control signal I/O lines. The multi-bit transmit data output is connected to the multi-bit transmit data input. One bit of the multi-bit transmit data output is connected to the single bit transmit data input. The multi-bit receive data input is connected to the multi-bit receive data output. One bit of the multi-bit receive data input is connected to the single bit receive data output. The parallel control signal I/O lines are connected to the parallel PHY control signal I/O lines. A subset of the parallel control signal I/O lines are connected to the serial PHY control signal I/O lines.

Media access controller capable of connecting to a serial physical layer device and a media independent interface (MII) physical layer device

A link control state machine controls a media access controller (MAC), a serial physical sublayer (serial PHY) and a media independent interface physical sublayer (MII PHY). In a first state of the link control state machine, an attempt is made to establish a link via the MII PHY. If successful, a second state is entered and the MAC performs data transfer using the MII PHY while the serial PHY is isolated from the MAC. In a third state, an attempt is made to establish a network link via a serial PHY. The MII PHY is isolated from the MAC and a test frame is sent using the serial PHY. The third state is entered from the first state when there is a link timeout on the MII PHY. In a fourth state, the MAC performs data transfer using the serial PHY. The fourth state is entered from the third state if the test frame was transmitted successfully.

Link control state machine for controlling a media access controller, a serial physical layer device and a media independent interface physical layer device

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Grass Valley, CA, United States of America

Eric McLaughlin