3par Inc.

David Chu

Christopher T Cheng

Michel P Cekleov

Greg L Dykema

A method for a mix mode driver to accommodate traces of different lengths includes storing in the mix mode driver a set of one or more control signals and coefficient signals for a trace length. The one or more control signals select a number of the stages to generate a variable amplitude data output signal. Each stage is operable to increase or decrease a data signal, and each of the coefficient signals determines the magnitude of increase or decrease of the data input signal by a stage. A method for operating the mix mode driver includes generating the variable amplitude data output signal with one or more of the stages, and providing the variable amplitude data output signal to a trace.

Mix mode driver for traces of different lengths

A method is provided to align clock and data signals over a source-synchronous link. The method includes sending header data and a default clock signal over the link. The header indicates a start of a training packet and the default clock signal ensures that the header is received without error. The method further includes providing a long clock pulse, phase shifting the clock signal during the long clock pulse, and thereafter sending training data and the clock signal over the link. The above steps are repeated until the training data are received with error. At that point, the phase shift of the clock signal is saved as a boundary of an optimal alignment. The above steps are then repeated with the clock signal shifted in a different direction. Once another boundary is located, the boundary midpoint is saved as the phase shift that provides the optimal alignment.

Trainable link

A method for a mix mode driver to accommodate traces of different lengths includes sequentially shifting values of a data signal to a number of stages and sequentially amplifying the values of the data signal at least one stage. Depending on the length of trace for the data signal, the method further includes providing at least one amplifying coefficient to at least one stage and coupling a subset of the stages to an adder. The method finally includes outputting the data signal from the adder to the trace.

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Santa Clara, CA, United States of America

David Chu