Patent ID: 6157939
Filing Date: 2000-12-05
Classification: G06F

Abstract:
A multiplier circuit for obtaining a multiplicative negate product (-B*C) and a multiplicative product (B*C) of a multiplicand B and a multiplier C, wherein the multiplier C includes at least one multiplier string, the multiplier circuit comprising:an encoder circuit having an input for receiving the multiplier C and having an output wherein the encoder circuit is adapted to identify the at least one multiplier string from the multiplier C and is adapted to provide on the encoder circuit's output an encoded multiplier string that corresponds to the at least one multiplier string;a multiplexor circuit coupled to the output of the encoder circuit, the multiplexor circuit being configured to pass the encoded multiplier string or a reordered string to an output of the multiplexor circuit in response to a control signal, wherein the multiplexor circuit creates the reordered string by reordering bits of the encoded multiplier string; anda binary multiplier circuit having an input coupled to receive the multiplicand B and an input coupled to receive the encoded multiplier string or the reordered string provided on the output of the multiplexor circuit, wherein the binary multiplier generates the multiplicative negate product (-B*C) in response to the reordered string and the multiplicand B, and generates the multiplicative product (B*C) in response to the encoded multiplier string and the multiplicand B.