ARITHMETIC PROCESSOR

摘要

PURPOSE:To attain the easy package of an arithmetic processor into an LSI by using a combination circuit containing the array of a small number of elements to form the arithmetic processor in order to minimize the transmission of the carry value and also to simplify a circuit constitution. CONSTITUTION:The basic arithmetic circuit of a single digit addition/subtraction forming an arithmetic processor uses the value of a control signal (q) to perform addition/subtraction. In other words, the part equivalent to the digit of the calculation expressed by an equation Z=X+Q(Y) is carried out by the basic arithmetic circuit. Here the X of a 1st member shows a redundant binary number and the Y of a 2nd member shows a redundant binary number containing non-negative digits excepting for the highest-order digit. Thus Q(Y)=Y and Q(Y)=-Y are satisfied with q=0 and q=1 respectively. Furthermore the addition is carried out for redundant binary numbers with q=0 and the subtraction is carried out between X and Y with q=1 respectively. Thus these operations are carried out by a same circuit.