1. An adaptive computing engine comprising: a first configurable computational unit including a first plurality of heterogeneous computational elements, the first plurality of heterogeneous computational elements including an adder, a register, and a function generator, the first plurality of heterogeneous computational elements coupled to each other via a first interconnection network to configure interconnections between the computational elements in response to configuration information to perform a first function; a second configurable computational unit for performing digital signal processing functions, the second computational unit including a second plurality of heterogeneous computational elements, the second plurality of heterogeneous computational elements including at least one multiplier computational element and at least one adder computational element, the second plurality of heterogeneous computational elements coupled to each other via a second interconnection network to configure the interconnections between the second plurality of heterogeneous computational elements in response to configuration information to perform a digital signal processing function; and a third interconnection network coupled between the first and second configurable computational units.