Method for storing the control code of a processor allowing effective code modification and addressing circuit therefor
US4751703A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 1986 |
| Grant date | Jun 14, 1988 |
| Priority date | — |
| Expiry date | Sep 16, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F8/66
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for storing the control code of a processor in a read only memory ROM (5) and in a read/write memory RAM (7) comprising a code area and a patch area. It consists in virtually dividing the control code in blocks of n instructions, storing the first instruction of each block into the code area of the read/write memory, and storing the n-1 following instructions of each block in the read only memory ROM. When an error is detected in at least one block, the first instruction of said block normally stored in the read/write RAM, is replaced by a branch instruction containing a branch address value so as to point to the patch area where the corrected block is stored. This method is implemented using a specific addressing circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.