High speed bidirectional signaling scheme

A computer system including memory, a CPU and a communications network coupled to said memory and said CPU wherein said communications network includes a plurality of component cores coupled to each other with data lines, each of said component cores comprising:

• a) a driver coupled to one of said data lines;
• b) reference means coupled to an input to said driver for generating a reference level, wherein said reference means inputs a reference control signal corresponding to an output of the component core to which it is coupled, said reference control signal being used to select one of a first and a second reference level;
• c) differential amplifier means having as a first input said selected reference level and having as a second input a signal on said data line for generating a difference signal.

A computer system including memory, a CPU and a communications network coupled to said memory and said CPU wherein said communications network includes a plurality of component cores coupled to each other with data lines, each of said component cores comprising:

• a) a driver coupled to one of said data lines;
• b) reference means coupled to an input to said driver for generating a reference level, wherein said reference means inputs a reference control signal corresponding to an output of the component core to which it is coupled and comprises a multiplexor which utilizes said reference control signal to select one of a pair of reference levels wherein said reference levels correspond to a digital subtraction of outgoing data from said component core from data incoming to said component core;
• c) differential amplifier means having as a first input said reference level and having as a second input a signal on said data line for generating a difference signal.

In a computer system including memory, a CPU and a communications network coupled to said memory and said CPU wherein said communications network includes a plurality of component cores coupled to each other with data lines, a method for transmitting data bidirectionally over a single data line comprising the steps of:

• a) coupling a driver to one of said data lines;
• b) generating a reference level based on an input to said driver, said reference level corresponding to a selected one of a pair of reference levels;
• c) generating a difference signal between said reference level and a signal on said data line.