Patent · US Expired

Processor structure and method for renamable trap-stack

US5673408A · kind A · utility

56Cited by
23References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 7, 1995
Grant dateSep 30, 1997
Priority date
Expiry dateJun 7, 2015

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F11/1407
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A data processor and associated method for taking and returning from traps speculatively. The data processor supports a predefined number of trap levels for taking nested traps each having a corresponding trap level. The data processor comprises means to form checkpoints, means to back up to the checkpoints, means to take a trap, means to return from a trap, registers, and a trap stack unit. The registers have contents that define the state of the data processor each time a trap is taken. The trap stack unit includes a trap stack data storage structure that has a greater number of trap slack storage entries than there are trap levels. It also includes a freelist unit that maintains a current availability list of the trap stack storage entries that are currently available for mapping to one of the trap levels. The freelist unit identifies, each time a trap is taken, a next one of the currently available trap stack storage entries for mapping to the corresponding one of the trap levels. The trap stack unit further includes read/write logic that writes, for each trap taken, the contents of the registers to the next one of the currently available trap stack storage entries. It still fu…

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