Restore PCIe transaction ID on the fly
US9075797B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 2013 |
| Grant date | Jul 7, 2015 |
| Priority date | — |
| Expiry date | Dec 2, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/382
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Restoring retired transaction identifiers (TID) associated with Direct Memory Access (DMA) commands without waiting for all DMA traffic to terminate is disclosed. A scoreboard is used to track retired TIDs and selectively restore retired TIDs on the fly. DMA engines fetch a TID, and use it to tag every DMA request. If the request is completed, the TID can be recycled to be used to tag a subsequent request. However, if a request is not completed, the TID is retired. Retired TIDs can be restored without having to wait for DMA traffic to end. Any retired TID value may be mapped to a bit location inside a scoreboard. All processors in the system may have access to read and clear the scoreboard. Clearing the TID scoreboard may trigger a DMA engine to restore the TID mapped to that location, and the TID may be used again.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.