Patent ID: 6272510
Filing Date: 2001-08-07
Classification: G06F

Abstract:
A correlation arithmetic unit in which when two integers satisfying 1.ltoreq.i.ltoreq.j are denoted by i and j; j variables are given in the form of x.sub.1, x.sub.2 . . . , x.sub.j ; and two functions are expressed by a (x.sub.1, x.sub.2 . . . , x.sub.j) and b(x.sub.1, x.sub.2 . . . , x.sub.j), an operation set forth below is applied to the two functions a (x.sub.1, x.sub.2 . . . , x.sub.j) and b (x.sub.1, x.sub.2 . . . , x.sub.j), ##EQU17##where an operation g*h between optional two numbers g and h stands for an operation for .vertline.g+h.vertline.-.vertline.g-h.vertline.;wherein said correlation arithmetic unit comprises an absolute value operation unit and a sign operation unit, wherein said absolute value operation unit comprises:an adder unit receiving input signals representing absolute value .vertline.a.vertline. and .vertline.b.vertline. of the two functions a and b, and outputting an addition signal representing a sum .vertline.a.vertline.+.vertline.b.vertline. of the two absolute values .vertline.a.vertline. and .vertline.b.vertline.;a first substracter unit receiving input signals representing absolute values .vertline.a.vertline. and .vertline.b.vertline. of the two functions a and b, and outputting a first subtraction signal representing a difference .vertline.a.vertline.-.vertline.b.vertline. between the two absolute values .vertline.a.vertline. and .vertline.b.vertline.;a difference-absolute value operation unit receiving the first subtraction signal, and outputting an absolute value signal represent an absolute value .vertline..vertline.a.vertline.-b.vertline..vertline. of the difference .vertline.a.vertline.-.vertline.b.vertline.; anda second subtracter unit receiving the addition signal and the absolute value signal, and outputting a second subtraction signal representing a difference .vertline.a.vertline.+.vertline.b.vertline.-.vertline..vertline.a.vertline .-.vertline.b.vertline..vertline., andwherein said sign operation unit outputs signals representing a plus and a minus in compliance with either one of a match and a mismatch of polarities ""sign (a) and sign (b)"" of the two functions a and b and the other respectively.