Polynomial circuit models for component matching in high-level synthesis

Design reuse requires engineers to determine whether or not an existing block implements desired functionality. If a common high-level circuit model is used to represent components that are described at multiple levels of abstraction, comparisons between circuit specifications and a library of potential implementations can be performed accurately and quickly. A mechanism is presented for compactly specifying circuit functionality as polynomials at the word level. Polynomials can be used to represent circuits that are described at the bit level or arithmetically. Furthermore, in representing components as polynomials, differences in precision between potential implementations can be detected and quantified. We present a mechanism for constructing polynomial models for combinational and sequential circuits. Furthermore, we derive a means of approximating the functionality of nonpolynomial functions and determining a bound on the error of this approximation. These methods have been implemented in the POLYSYS synthesis tool and used to synthesize a JPEG encode block and infinite impulse response filter from a library of complex elements.