The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 30, 1987
Filed:
Jun. 27, 1984
Toru Ohtsuki, Hadano, JP;
Yoshio Oshima, Hadano, JP;
Sako Ishikawa, Hadano, JP;
Hideaki Yabe, Hadano, JP;
Masaharu Fukuta, Hadano, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An apparatus for decimal multiplication divides a multiplier of binary coded decimal (BCD) into plural groups, generates plural partial products of which are multiplied a multiplicand of BCD and the plural groups of multiplier over successive cycles and adds them to an intermediate product which is a summation of the previously generated partial products. The addition of the partial product and the intermediate product is made by a carry save adder. At a first cycle, the intermediate product is set to zero, and the addition of 6 is made to each digit of either one of the intermediate product sum and the partial product, and the addition of the partial product and the intermediate product is made by a carry save adder loop over successive cycles. At a final cycle, the sum and carry from the carry save adder are added by a full adder, and the subtraction of 6 is made for each digit according to the existence of carry transfer in each digit of the full adder and the resultant value is output as a multiplication result.