Patent ID: 8917762

Claim:
A decision feedback equalizer (DFE) slice for a receiver, comprising: a plurality of non-speculative DFE taps; and 3 speculative DFE taps, wherein the 3 speculative DFE taps comprise first and second multiplexer stages, each of the first and second multiplexer stages comprising: 4 comparator latches, each of the 4 comparator latches having a programmable offset; and a multiplexer that receives 4 comparator latch outputs from the 4 comparator latches and outputs a multiplexer stage output, wherein the multiplexer is controlled by previous symbol decisions d n-2 and d n-3 , wherein the previous symbol decisions d n-2 and d n-3 are received from two other respective DFE slices in the receiver; and wherein the 3 speculative taps further comprise a 2:1 decision multiplexer stage that receives the multiplexer stage outputs of the first and second multiplexer stages and is controlled by a previous symbol decision d n-1 received from a third respective DFE slice in the receiver to output a slice output signal d n , and wherein the first multiplexer stage further comprises a spare comparator latch, the spare comparator latch comprising a configurable offset, wherein the spare comparator latch is configured to be swapped in for a subgroup of the other comparator latches in the first multiplexer stage, and wherein the wherein the first multiplexer stage comprises a 5:1 multiplexer.