Patent ID: 7068726

Claim:
Apparatus for a bi-directional communication link having a plurality of channels, each of said channels comprising: a master connected at a near end of the channel and a slave connected at an opposite end of the channel, said master comprising: (a) a first transmitter coupled to the channel and having a master Tx clock signal; and (b) a first receiver coupled to the channel and comprising; (i) an analog-to-digital (A/D) converter that periodically samples a signal incoming over the channel to yield a received signal; (ii) a clock recovery circuit that generates a master Rx clock from a clock signal embedded in the received signal; and (iii) a metric processor, connected to an output of said A/D converter, that produces a metric signal reflective of amplitude differences between the received signal and allowed amplitude levels for the received signal; and said slave comprising: (a) a second receiver coupled to the channel and comprising a clock recovery circuit for generating a Slave Rx clock from a signal received over the channel and transmitted from the master; (b) a second transmitter coupled to the channel and having a Slave Tx clock signal, said master Rx clock signal being frequency locked to said Slave Tx clock signal; and (c) a first delay element for generating said Slave Tx clock signal by controllably delaying said Slave Rx clock signal; and wherein said apparatus further comprises a decision processor, connected to said master and responsive to said metric signal, for determining a delay value to be provided by said first delay element in the slave which will maximize the metric signal and issuing a command, via the first transmitter and the channel, to said second receiver in order to set a delay provided by said first delay element to said delay value, so as to reduce distortion caused by near end cross-talk and echo in signals received over the channel, by the first receiver and thus facilitate clock and data recovery by the first receiver.