Method and apparatus for bus contention resolution
US4642630A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1982 |
| Grant date | Feb 10, 1987 |
| Priority date | — |
| Expiry date | Dec 28, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L12/413
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for bus contention resolution for use in a digital communications system wherein a plurality of communications controllers are connected to a shared bus for transmitting information in frames. A priority field is included in each transmitted frame. The bus is monitored such that any time the bus is conveying a frame, the priority field of that frame is known at each of the communications controllers. A given communications controller makes a determination based on the priority fields of a new frame and a present frame being actively conveyed by the shared bus that the new frame is of higher priority than the present frame. Upon such a determination, the given communications controller transmits the new frame. In accordance with a second aspect of the method and apparatus, the bus has the characteristic that when any communications controller connected thereto transmits a predetermined logic value, the bus conveys that predetermined logic value regardless of logic values transmitted by other communications controllers. Each communications controller monitors the bus and counts the number of consecutive bits conveyed thereon having the predetermined logic value…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.