Patent ID: 7386240
Filing Date: 2008-06-10
Classification: H04B

Abstract:
1. A digital filter comprising: one or more functional units, each functional unit being associated with a lookup table of filter coefficient values, each functional unit to process an input data stream using the filter coefficient values in the lookup table and to generate one or more output data streams for transmission on an optical link: and wherein the lookup table is a multi-port memory having a plurality of multi-bit read ports, each read port storing a filter coefficient value: wherein each functional unit further comprises: a linear tree adder to process a portion of the input data stream, the linear tree adder including a piurality of adders, each adder having an input for receiving one of a first input sample value and a second input sample value, and an output for providing a partial sum: and further comprising: a final adder having a first input for receiving a final partial sum from a last one of the plurality of adders in the linear tree adder, a second input for receiving a filter coefficient value from the lookup table, and an output for providing a final sum.