Indirect literal expansion for computer instruction sets
US5072372A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 3, 1989 |
| Grant date | Dec 10, 1991 |
| Priority date | — |
| Expiry date | Mar 3, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/30167
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A digital data processor executes fixed-length instructions containing either a direct literal or part of an address specifying an indirect literal stored in memory. The balance of the address of the indirect literal preferably is provided by the value of the program counter. A direct-indirect control bit contained in the instruction indicates whether a direct literal or indirect literal is specified by the literal field. In processing an instruction, the processor preferably treats the literal field contents as though it contained both direct literal bits and address bits for specifying an indirect literal. The processor uses the direct/indirect literal control bit to determine whether to pass the literal field contents or the fetched entry from the memory for further processing. In this way, the processor can obtain, for instance, either short direct literals or long indirect literals in an expeditious manner in the same number of cycles. Other embodiments of the invention provide processors for executing, in a novel manner, instructions each containing only a single indirectly-specified literal or two literals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.