Data dependency detection and handling in a microprocessor with write buffer
US5471598A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 1993 |
| Grant date | Nov 28, 1995 |
| Priority date | — |
| Expiry date | Oct 18, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3875
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A superscalar superpipelined microprocessor having a write buffer located between the core and cache is disclosed. The write buffer is controlled to store the results of write operations to memory until such time as the cache becomes available, such as when no high-priority reads are to performed. The write buffer includes multiple entries that are split into two circular buffer sections for facilitating the interaction with the two pipelines of the core; cross-dependency tables are provided for each write buffer entry to ensure that the data is written from the write buffer to memory in program order, considering the possibility of prior data present in the opposite section. Non-cacheable reads from memory are also ordered in program order with the writing of data from the write buffer. Features for handling speculative execution, detecting and handling data dependencies and exceptions, and performing special write functions (misaligned writes and gathered writes) are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.