Method and apparatus for equalizing a high speed serial data link

An apparatus for equalizing a reflection in a reflective serial link, comprising:

• a programmable delay element having an input port and an output port, the input port in electrical communication with a transmitter output of a transmitter of a high speed serial link;
• a driver stage having a driver input and a driver output, the driver input in electrical communication with the output port of the programmable delay element and the driver output in electrical communication with a channel input of a channel of the high speed serial link;
• and
• wherein the programmable delay element is configured to delay a pulse transmitted by the transmitter by delay time T and forward the delayed pulse to the driver stage and wherein the driver stage is configured to transmit a compensating pulse over the channel by adjusting an amplitude of the delayed pulse;
• the delay time T determined by:
• setting a time delay to an initial delay, the time delay related to when the compensating pulse is transmitted after the pulse is transmitted;
• transmitting a test pattern to generate an eye pattern at a receiver of the high speed serial link;
• determining a set of parameters of the eye pattern;
• determining a figure of merit for the time delay based, at least in part, on the set of parameters;
• and
• setting delay time T to the time delay having the highest figure of merit.

A method for equalizing a plurality of reflections in a reflective high speed data serial link, comprising:

• obtaining a first delay time T1 for a first compensating pulse;
• obtaining a first amplitude A1 for the first compensating pulse;
• transmitting the first compensating pulse, having an amplitude A1, at a time T1 after a pulse is transmitted on the reflective high speed data serial link;
• obtaining a second delay time T2 for a second compensating pulse;
• obtaining a second amplitude A2 for the second compensating pulse;
• and
• transmitting the second compensating pulse, having an amplitude A2, at a time T2 after the pulse is transmitted on the reflective high speed data serial link;
• wherein obtaining the delay time T1 comprises:
• setting a time delay to an initial delay, the time delay related to when the compensating pulse is transmitted after the pulse is transmitted on the reflective high speed data serial link;
• transmitting a test pattern to generate an eye pattern at a receiver;
• determining a set of parameters of the eye pattern;
• determining a figure of merit for the time delay based, at least in part, on the set of parameters;
• and
• setting T1 to the time delay having the highest figure of merit.