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

Abstract

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.