Shift amount floating-point calculating circuit with a small amount of hardware and rapidly operable
US5166898A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 6, 1991 |
| Grant date | Nov 24, 1992 |
| Priority date | — |
| Expiry date | Sep 6, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F5/012
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a floating-point arithmetic unit for performing floating-point arithmetic of first and second input data which are represented by a floating-point representation and composed of first and second exponent parts and first and second mantissa parts, a shift amount calculating circuit comprises first and second substractors (26, 27) supplied with lower (n+1) bits of the first and the second exponent parts. The first subtracter subtracts a first lower number (#EA1) from a second lower number (#EB1) to produce a first difference signal (RS1). The second subtracter subtracts the second lower number (#EB1) from the first lower number (#EA1) to produce a second difference signal (RS1). Supplied with the first and the second exponent parts, an exponent comparing unit (28) compares the first exponent part with the second exponent part to produce a comparison result signal (CP1, CP2, CP3, CP4). Responsive to the comparison result signal, a first selector (31) selects one of the first difference signal and first and second value signals ("0", "64" ) as a first right-shift amount signal (SD1). Responsive to the comparison result signal, a second selector (32) selects one of the second differe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.