Exponential function computing apparatus
US4225933A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 16, 1978 |
| Grant date | Sep 30, 1980 |
| Priority date | — |
| Expiry date | Nov 16, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F7/556
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus for computing an exponential function a.sup.x with an N radix computer where a represents a positive constant and where X is a variable. The apparatus includes an X register for storing X and a generator which sequentially generates the logarithmic value log.sub.a (1+N.sup.-k) or N.sup.k .multidot.log.sub.a (1+N.sup.-k) for values of k raning from o to m. Subtracting apparatus is provided which, for each logarithmic value generated, repeatedly subtracts the logarithmic value from the contents of the X register and stores the remainder in the X register until the contents of the register are less than the logarithmic value. The number of such repeated subtractions performed for each logarithmic value generated is stored in a Z register. A data shifting and adding apparatus is provided which upon termination of the repeated subtractions, sets an initial value in the X register and performs a sequence wherein a value is stored in a Y register which corresponds to the contents of the X register, the contents of the Y register are shifted k number of digits and the shifted contents are added to the contents of the X register. Such sequence is performed once for each of the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.