Numeric processor including a multiply-add circuit for computing a succession of product sums using redundant values without conversion to nonredundant format

摘要

A numeric processor includes a multiply-add circuit with redundant value interface circuitry for performing mathematical function computations as a succession of product sums using redundant binary format values (such as signed digit) as the multiplicand and/or the addend inputs to the multiply-add circuit. The redundant value interface circuitry (i) extracts a predetermined number of bits from a redundant product sum to form a redundant truncated product sum, and (ii) couples the redundant truncated product sum to either, or both, multiplicand and addend inputs. In this manner, successive redundant product sums are calculated using without conversion to nonredundant binary format. In a preferred embodiment, the numeric processor includes a single multiply- add circuit, with redundant truncated product sum values being fed back to the multiplicand and/or addend inputs.