Advanced Micro Devices Corporation

Michael Richard Bray

Qing He

Geetha N Rangan

A novel method of operating a physical layer device in a local area network, such as one conforming to Ethernet protocol, to make a single physical layer device compatible with Physical Media Dependent (PMD) devices operating over different network media types. The methodology involves monitoring signal detect inputs and based on their levels, automatically reconfiguring the physical layer device to support interface to a required PMD device. In a preferred embodiment, a physical layer device in a network transceiver for interconnecting a hub device and PMD devices has first transmitting and receiving paths for supporting interface to a first PMD device, such as 100 BASE-TX, and second transmitting and receiving paths for supporting interface to a second PMD device, such as 100 BASE-FX.

Network transceiver using signal detect input to control modes of operation

A novel network transceiver having a Media Independent Interface (MII) operating at 10 Mb/s or 100 Mb/s for connecting the transceiver to a repeater or hub device. A serial interface select signal can be asserted to configure the MII to operate as a General Purpose Serial Interface (GPSI) for 10 Mb/s data. The least significant transmit and receive data pins of the MII are respectively mapped to transmit and receive data pins of the GPSI. A circuit for enabling MII to operate in a GPSI mode has a transmit multiplexer controlled by the serial interface select signal to bypass a parallel-to-serial converter that transforms parallel transmit MII data into a serial data stream, and a receive multiplexer controlled by the serial interface select signal to bypass a serial-to-parallel converter that transforms serial receive data stream into parallel receive MII data.

Network transceiver having media independent interface operable in a general purpose serial interface mode

A novel method of operating physical layer devices in a local area network, such as one conforming to Ethernet protocol, in which there are a plurality of repeaters of respectively different data rates for communicating with a link partner on a network medium via the physical layer devices. Each physical layer device is prevented from communicating with the repeaters, when a change in the operating speed of the physical layer device is detected. Then, status information of the physical layer device is determined, and the physical layer device is enabled to communicate with a selected one of the repeaters having a data rate conforming to the operating rate of the physical layer device. In a preferred embodiment, each physical layer device has a variable operating speed selected depending on the operating speed of the link partner. A plurality of busses corresponding, respectively, to the speeds of operation of the repeaters, are provided for interconnecting the repeaters and the physical layer devices. A multiplexer interconnects each of the physical layer devices to a selected one of the plurality of busses. In response to a change in the operating speed of the physical layer device, handshake logic automatically prevents the physical layer device from communicating with the repeaters until one of the repeaters is ready to communicate with the physical layer device. The handshake logic enables the repeaters to read status information of the physical layer device and change its connection to the repeaters, based on the status information.

Handshaking between repeater and physical layer device in a variable rate network transceiver

A novel multi-port network transceiver having an LED interface supporting parallel and serial LED modes. The LED interface has a pair of LED pins for each port. In the parallel LED mode, one pin of this pair represents status of a 10 Mb/s communication, whereas another pin represents status of a 100 Mb/s communication. In the serial LED mode, status information for all ports is transferred using 3 pins supplying a serial data stream, a frame signal and a clock signal. The serial data stream is composed of frames, each of which represents various events for the multiple ports. The frame signal is used to identify the boundary between the frames. The transfer of the serial data stream is synchronous to the clock signal.

Network transceiver having a LED interface operable in parallel and serial modes

A novel system for selectively referencing transmit data transferred from a repeater to a physical layer transmitter via a Media Independent Interface (MII), to an input clock selected depending on a mode of MII operations. A clock select input determines whether transmit data is referenced to a selected input clock or to a MII transmit clock output. An analog phase-locked loop (APLL) is supplied with the selected input clock to produce a signal for driving a wave shaper that converts the MII transmit data into a required format for 10 Mb/s operations.

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San Jose, CA, United States of America

Michael Richard Bray