Multi-user data processing system with storage protection
US5991858A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 31, 1997 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Dec 31, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/1441
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A data processor is adapted, in particular with respect to the microcode, in such a way that the execution of standard commands of the processor which are loaded in a user memory area and request reading or writing access to the content of memory cells is inhibited. In the operating system memory area there is a memory area access table, in which there is stored the address area authorized per user memory area for the commands there. Finally, there is an additional program routine which is called up by a command loaded in a user memory area and requesting reading or writing access to a memory cell, and checks by means of the memory area access table (before execution) whether the requested access to a memory cell lies in the authorized address area. If it does not lie in the authorized address area, the additional program routine inhibits the execution of the command. The invention has the advantage that the "radius of action" of one or more application programs in the user program memory area can be restricted in a simple way.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.