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:
Mar. 13, 1984
Filed:
Jul. 10, 1981
Osamu Onodera, Hadano, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A data processing apparatus for performing decimal arithmetic operation with the aid of a decimal arithmetic unit having an operation width corresponding to a plurality of bytes. Length value of an operand which is to undergo arithmetic operation of the decimal arithmetic unit is held in an operand length register, while a byte position which constitutes the least significant position in the arithmetic operation is held in an operand point register. An overflow detection controlling circuit generates a control signal in accordance with the contents in both the registers. An overflow detecting circuit detects presence or absence of an overflow by checking a particular byte contained in the output of the decimal arithmetic unit, the particular byte being designated by the control signal produced from the overflow detection controlling circuit.