Microprocessor implemented data processing system capable of emulating execution of special instructions not within the established microprocessor instruction set by switching access from a main store portion of a memory
US4972317A · kind A · utility
17Cited by
21References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1989 |
| Grant date | Nov 20, 1990 |
| Priority date | — |
| Expiry date | Aug 4, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3889
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A microprocessor chip which is capable of executing a specific subset of instructions on behalf of the main storage portion of a computer memory can be made to emulate direct execution instructions not in that specific subset while working on behalf a control storage portion of the computer memory in a manner which is transparent to the main storage portion by means of a novel set of operand space selection instructions in the control storage portion and a novel switching circuit on the microprocessor chip which controls the access of the chip to the control store portion and the main store portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.