Arithmetic circuit for calculating and accumulating absolute values of the difference between two numerical values.

摘要

Described is an arithmetic circuit for calculating and accumulating absolute values of a difference between a first and a second numerical value having a predetermined bit length and represented by 2's complement notation and outputting an accumulation result as an operation result. Said circuit comprises a first inverter for inverting the second numerical value to produce an inverted value. A first adder produces a sum of the first numerical value and inverted value and outputs the sum as a first addition result. A second inverter inverts the first addition result to output an inverted addition result. A selector selects either one of the inverted addition result and first addition result on the basis of the sign of the first addition result and outputs the one result as a selected value. A correcting value generating circuit outputs a correcting value on the basis of the sign of the first addition result. A second adder produces a sum of the selected value, the correcting value and a delayed addition result and outputs the sum as a second addition result. A first delay circuit delays the second addition result by a predetermined delay to produce the delayed addition result while outputting the delayed addition result as the operation result. This arithmetic circuit is simple in construction and is operable at a high speed and with a minimum of power consumption.