Patent ID: 6157652
Filing Date: 2000-12-05
Classification: H04J,H04L

Abstract:
A hub port for connecting a hub to a node port, where the hub includes at least two hub ports interconnected in a loop with internal hub links, the hub port comprising:(a) a hub clock line connected to a local clock internal to the hub for supplying a local clock signal;(b) a multiplexer which includes a first data input, a second data input, a third data input, and a control input;(c) a hub output register connected to the multiplexer, and to the hub clock line;(d) an incoming internal hub link connected to the third data input of the multiplexer;(e) an outgoing internal hub link connected to the hub output register;(f) a transmit circuit connected to the incoming internal hub link and to the hub clock line;(g) an encoder connected to the transmit circuit and to the hub clock line;(h) a current fill word generator connected to the second data input of the multiplexer and to the hub clock line;(i) a fill word detect circuit connected to the current fill word generator;(j) a smoothing buffer connected to the first data input of the multiplexer, the current fill word generator, the fill word detect circuit, and to the hub clock line;(k) a smoothing control circuit connected to the smoothing buffer;(l) a hub port output control circuit connected to the smoothing control circuit and the control input of the multiplexer;(m) a word synchronization detect circuit connected to the smoothing control circuit;(n) a receive circuit connected to the word synchronization detect circuit and the smoothing buffer;(o) a decoder connected to the receive circuit; and(p) a serializer/deserializer circuit connected to the encoder, the decoder, the node port, and to the hub clock line, where the serializer/deserializer circuit includes a recovered clock output connected to the decoder, the word synchronization detect circuit, and the smoothing buffer.