1. A device having programmable resources for implementing arithmetic functions, the device comprising: an input port coupled to receive a configuration bitstream; and a plurality of configurable arithmetic blocks each having a plurality of multiplexers, wherein each multiplexer of the plurality of multiplexers of a configurable arithmetic block is coupled to select a bit of a serial input data stream or a bit of a multiple bit input word based upon the configuration bitstream, and wherein the configurable arithmetic block comprises input registers coupled to outputs of the plurality of multiplexers to receive the multiple bit input word or input bits of the serial input data stream, and comprises an arithmetic function circuit for implementing arithmetic functions on the multiple bit input word according to bits of the configuration bitstream.