Using two barrel shifters to implement shift, rotate, rotate with carry, and shift double as specified by the X86 architecture
US6304956A · kind A · utility
22Cited by
9References
31Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 25, 1999 |
| Grant date | Oct 16, 2001 |
| Priority date | — |
| Expiry date | Mar 25, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F5/01
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A novel method and apparatus of performing data bit moving functions on a data word using two barrel shifters: a left shifter and a right shifter. The present invention is able to handle both shift and rotate functions using one shifter unit. Specifically, for shift functions, only one of the two shifters is used to perform the shifting function. On the other hand, for rotate functions, both shifters are needed for shifting the data word. The amounts of the right shift and left shift depend on the number defined by the count operand and the specific shift/rotate instruction requested.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.