Register stacking in a computer system
US5640582A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1994 |
| Grant date | Jun 17, 1997 |
| Priority date | — |
| Expiry date | Aug 17, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/462
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A computer system provides an expanded register set by employing transparent register stacks for each general purpose register. Each general purpose register and its corresponding set of auxiliary registers form a register stack. No register identification bits are required in processor instructions to reference auxiliary registers. A register set select storage area is a programmable register provided for the storage of a value that identifies the currently active register level. The register set select storage area is loaded using two additional processor instructions provided as part of the present invention. A register set switch is used for selecting a data path to the register level specified by the register set select storage area. A PUSHREG instruction is used to push the register stack pointer down one level. A POPREG instruction is used to move the register stack pointer up one register level. In a alternative embodiment of the present invention, the POPREG and PUSHREG instructions include an argument that specifies the single register stack that is manipulated. In another embodiment of the present invention, register stack underflow or overflow conditions are trapped usi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.