Patent · US Expired

Two store data storage apparatus having a prefetch system for the second store

US4729092A · kind A · utility

5Cited by
10References
6Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 17, 1985
Grant dateMar 1, 1988
Priority date
Expiry dateMay 17, 2005

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F9/262
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Data storage apparatus comprises a main store, for example a microprogram store, with an associated address generating circuit. In order to extend the capacity of the store, an additional store is provided, but because of physical limitations this is remote from the main store. To reduce delays in accessing data items from the additional store, a prediction circuit predicts the address of the next item to be required from the additional store and prefetches it. A control circuit checks whether the prefetched item is the correct one and, if it is not, causes a temporary hold-up in the operation of the address generation circuit to allow the correct data item to be fetched.

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