Patent ID: 7158566
Filing Date: 2007-01-02
Classification: H04L

Abstract:
1. A second semiconductor chip for use in equalizing a transfer function of an inter-chip high-speed bus wire trace on a circuit board, wherein the inter-chip high-speed bus wire trace electrically couples an output pad of a first semiconductor chip to an input pad of the second semiconductor chip, the second semiconductor chip comprising: the input pad that couples to the inter-chip high-speed bus wire; a 1-bit sampling circuit coupled to said input pad and operative to convert an analog signal received on said input pad to a stream of 1-bit digital sample values, wherein the sampling circuit produces its stream of 1-bit digital sample values at a specified sampling rate; an equalizer that processes said stream of 1-bit digital sample values using a feed forward filter channel that includes a multiplier free adder-based circuit that combines a set of equalizer coefficients of a coefficient vector with one or more of the 1-bit digital sample values to produce a recovered signal sequence, wherein the recovered signal sequence has a reduced sample rate that is at least two times less than said specified sampling rate, wherein said equalizer further comprises at least one decision feedback stage which adds a decision feedback component to the recovered signal sequence to compute an estimated symbol sequence, and wherein the equalizer is characterized in that its coefficient vector substantially minimizes a measure of a residual error signal; and a decision circuit coupled to receive the estimated symbol sequence and operative to generate a stream of recovered symbol values.