Microprocessor and method of using a segment override prefix instruction field to expand the register file
US5822778A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1997 |
| Grant date | Oct 13, 1998 |
| Priority date | — |
| Expiry date | Jul 1, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3844
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A microprocessor is provided which is configured to detect the presence of segment override prefixes in instruction code sequences being executed in flat memory mode, and to use the prefix value or the value stored in the associated segment register to control the selection of a bank of registers to use for the instruction operands. Each bank of registers includes the full complement of AMD 80x86 Series registers. Additional registers are available to a program other than the AMD 80x86 Series architecture specifies, but the instruction encoding is unchanged. Having more registers available to a program allows for more operands to be stored in the registers. Since registers are accessible in a shorter period of time than memory, operand access time is decreased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.