Direct memory access (DMA) address translation with a consecutive count field
US9348759B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2013 |
| Grant date | May 24, 2016 |
| Priority date | — |
| Expiry date | Aug 6, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/657
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
DMA translation table entries include a consecutive count (CC) field that indicates how many subsequent translation table entries point to successive real page numbers. A DMA address translation mechanism stores a value in the CC field when a translation table entry is stored, and updates the CC field in other affected translation table entries as well. When a translation table entry is read, and the CC field is non-zero, the DMA controller can use multiple RPNs from the access to the single translation table entry. Thus, if a translation table entry has a value of 2 in the CC field, the DMA address translation mechanism knows it can access the real page number (RPN) corresponding to the translation table entry, and also knows it can access the two subsequent RPNs without the need of reading the next two subsequent translation table entries.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.