Opcode to turn around a bi-directional bus
US6895458B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 4, 2002 |
| Grant date | May 17, 2005 |
| Priority date | — |
| Expiry date | May 6, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T15/005
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system for managing the control of a bi-directional data bus between a master unit and a slave unit. The master couples to the slave through a request opcode bus, a reply opcode bus and the data bus. If the master is in a bus driving state (with respect to the data bus) and receives a read request, the master relinquishes bus control and sends a read request through the request opcode bus. The slave unit assumes bus control and sends the requested data through the data bus. If the master is in a bus sensing state and receives a write request, the master sends a last read opcode to the slave via the request opcode bus, and waits for the slave to return a special token through the reply opcode bus. Upon receiving the special token the master unit assumes bus control and performs the write transaction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.