Speculative cache tag evaluation
US7840874B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 27, 2006 |
| Grant date | Nov 23, 2010 |
| Priority date | — |
| Expiry date | Aug 16, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/1064
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A cache tag comparison unit in a cache controller evaluates tag data and error correction codes to determine if there is a cache hit or miss. The cache tag comparison unit speculatively compares the tag data with the request tag without regard to error correction. The error correction code verifies whether this initial comparison is correct and provides a confirmed cache hit or miss signal. The tag data is compared with the request tag to determine a provisional cache hit or miss, and in parallel, the error correction code is evaluated. If the error code evaluation indicates errors in the tag data, a provisional cache hit is converted into a cache miss if errors are responsible for a false match. If the error code evaluation identifies the locations of errors, a provisional cache miss is converted into a cache hit if the errors are responsible for the mismatch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.