Method and apparatus for arbitrating requests at two or more levels of priority using a single request line
US5805905A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1995 |
| Grant date | Sep 8, 1998 |
| Priority date | — |
| Expiry date | Sep 6, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D10/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Method and apparatus for arbitrating for a shared resource among two or more devices, wherein one device can arbitrate at two or more different levels of priority at different times. Only two conductors are used to communicate between the device and the arbiter: one request signal line and one grant signal line. In order to assert a request for control of memory, the device brings the request signal line to a predefined logic level. The arbiter considers this a low priority request for control of the shared resource, and the arbitration proceeds accordingly. Then, if the device's request is a high priority request, or if it was originally a low priority request and has now become a high priority request, the device brings the request signal to the opposite logic level to thereby increase the priority level of its request. In either case, the arbiter grants control of the shared resource by asserting the device grant signal to the device. Only two wires are required for the dual priority device to participate in the arbitration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.