Scan chains for out-of-order load/store execution control
US6038657A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 1998 |
| Grant date | Mar 14, 2000 |
| Priority date | — |
| Expiry date | Mar 17, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/4812
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Scan logic which tracks the relative age of stores with respect to a particular load (or of loads with respect to a particular store) allows at processor to hold younger stores until the completion of older loads (or to hold younger loads until completion of older stores). Embodiments of propagate-kill style lookahead scan logic or of tree-structured, hierarchically-organized scan logic constructed in accordance with the present invention provide store older and load older indications with very few gate delays, even in processor embodiments adapted to concurrently evaluate large numbers of operations. Operating in conjunction with the scan logic, address matching logic allows the processor to more precisely tailor its avoidance of load-store (or store-load) dependencies. In a processor having a load unit and a store unit, a load/store execution control system allows load and store instructions to execute generally out-of-order with respect to each other while enforcing data dependencies between the load and store instructions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.