Priority circuit for channel subsystem having components with diverse and changing requirement for system resources
US4675812A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1985 |
| Grant date | Jun 23, 1987 |
| Priority date | — |
| Expiry date | Dec 20, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/18
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A priority circuit handles requests by three components of a data processing system for access to several resources of the system that can be accessed one at a time on each operating cycle of the system. A logic circuit receives requests by the requesters and grants access to one requester on a priority basis. The logic circuit has means for establishing a particular priority sequence, and the priority circuit includes means for stepping the logic circuit through a cycle of different priority sequences. In a repeating cycle of these steps, each requester is given the highest priority at least once. In a specific embodiment, the stepping means is a counter and a cycle is called a counting cycle. The stepping means is responsive to a control code to establish a particular stepping sequence. In a longer sequence, the lowest priority requester is given the highest priority once and higher priority requesters are given the highest priority several times so that in a complete cycle of steps the requesters have a different relative priority. In shorter cycles, the lowest priority requester is still given highest priority once and the higher priority requesters are given highest priority a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.