Patent · US Expired

Apparatus and method for performing a shift operation in a multiplier array circuit

US4887232A · kind A · utility

15Cited by
5References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 15, 1987
Grant dateDec 12, 1989
Priority date
Expiry dateMay 15, 2007

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F7/49947
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

In floating point operations, it is necessary to align the fractions of the floating point operands before addition or subtraction operations can be executed. This fraction alignment is performed by a shifting operation, typically using dedicated apparatus such as a barrel shifter. While the dedicated apparatus provides high performance in the execution of the shifting operation, this performance is accomplished by reserving a portion of the substrate area for apparatus implementation. To avoid the use of dedicated apparatus, the shifting operation is performed in a multiplier unit, according to the present invention, by entering the number to be shifted in the multiplicand register of the multiplier unit while entering appropriate control signals in the multiplier register. In this manner, a shifting operation can be performed without dedicated apparatus and with minor impact on performance.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.