Data processing apparatus and method for cache line replacement responsive to the operational state of memory
US6490655B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 13, 1999 |
| Grant date | Dec 3, 2002 |
| Priority date | — |
| Expiry date | Sep 13, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/18
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A data processing system 2 is described including a cache memory 8 and a plurality of DRAM banks 16, 18, 20, 22. A victim select circuit 32 within a cache controller 10 selects victim cache storage lines 28 upon a cache miss such that unlocked cache storage lines are selected in preference to locked cache storage lines, non-dirty cache storage lines are selected in preference to dirty cache storage lines, and cache storage lines requiring a write back to a non-busy DRAM bank are selected in preference to cached storage lines requiring a write back to a busy DRAM storage bank. A DRAM controller 24 is provided that continuously performs a background processing operation whereby dirty cache storage lines 28 within a cache memory 8 are written back to their respective DRAM banks 16, 18, 20, 22 when these are not busy performing other operations and when the cache storage line has a least recently used value below a certain threshold. A bus arbitration circuit 12 is provided that re-arbitrates bus master priorities in dependence upon determined latencies for respective memory access requests. As an example, if a high priority memory access request results a cache miss, with a lower prio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.