Patent · US Expired

System for explicitly referencing a register for its current content when performing processor context switch

US6199156A · kind A · utility

21Cited by
4References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 16, 1998
Grant dateMar 6, 2001
Priority date
Expiry dateDec 16, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F9/461
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

In a data processing system that includes a safe store buffer containing valid copies of all registers, processor transitions from a higher security routine to a lower security routine can be performed in fewer cycles by loading the safe store buffer from a safe store stack frame, then delaying loading registers either until actually utilized, or by a background process that loads registers utilizing unused memory cycles. A flag is used for each register that indicates whether the register contents are valid. This flag is cleared for each of the registers whenever such a state transition is made. Then, the flag is set for a register when it is referenced and made valid.

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