Accelerated graphics port multiple entry gart cache allocation system and method
US5949436A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1997 |
| Grant date | Sep 7, 1999 |
| Priority date | — |
| Expiry date | Sep 30, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/1081
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A computer system having a core logic chipset that functions as a bridge between an Accelerated Graphics Port ("AGP") bus device such as a graphics controller, and a host processor and computer system memory wherein a Graphics Address Remapping Table ("GART table") is used by the core logic chipset to remap virtual memory addresses used by the AGP graphics controller into physical memory addresses that reside in the computer system memory The GART table enables the AGP graphics controller to work in contiguous virtual memory address space, but actually use non-contiguous blocks or pages of physical system memory to store textures, command lists and the like. The GART table is made up of a plurality of entries, each entry comprising an address pointer to a base address of a page of graphics data in memory. The core logic chipset may cache a subset of the most recently used GART table entries to increase AGP performance when performing the address translation. When a GART table entry is not found in the cache, a memory access is required to obtained the needed GART table entry. There are two GART table entries in each quadword returned in toggle mode of the cacheline of memory inform…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.