Patent · US Expired

System for monitoring program flow utilizing fixwords stored sequentially to opcodes

US6044458A · kind A · utility

9Cited by
4References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 12, 1997
Grant dateMar 28, 2000
Priority date
Expiry dateDec 12, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F11/28
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A processing system includes a control flow monitor (CFM) checker for verifying a sequence of instructions performed by a pipelined processor (101). The CFM checker provides fail safe assurance against run-time errors in the sequence of instructions performed by a processor. The CFM checker verifies instruction sequence during run-time within 32 instruction cycles. The processing system provides an improved system and method having a CFM checker which minimizes wasted instruction cycles when performing branch instructions in a software program. Using a prefetch capability of an instruction pipeline and storing fixwords sequentially in memory, eliminates unnecessary instructions to fetch fixword values from external tables, thereby saving instructions and instruction cycles.

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