Patent · US Expired

System for delaying processing of memory access exceptions until the execution stage of an instruction pipeline of a virtual memory system based digital computer

US4985825A · kind A · utility

94Cited by
7References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 3, 1989
Grant dateJan 15, 1991
Priority date
Expiry dateFeb 3, 2009

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F12/1045
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A technique for processing memory access exceptions along with pre-fetched instructions in a pipelined instruction processing computer system is based upon the concept of pipelining exception information along with other parts of the instruction being executed. In response to the detection of access exceptions at a pipeline stage, corresponding fault information is generated and transferred along the pipeline. The fault information is acted upon only when the instruction reaches the execution stage of the pipeline. Each stage of the instruction pipeline is ported into the front end of a memory unit adapted to perform the virtual-to-physical address translation; each port being provided with storage for virtual addresses accompanying an instruction as well as storage for corresponding fault information. When a memory access exception is encountered at the front end of the memory unit, the fault information generated therefrom is loaded into the storage and the port is prevented from accepting further references.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.