Patent · US Expired

Semaphores with interrupt mechanism

US6874049B1 · kind B1 · utility

7Cited by
6References
6Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 1, 2002
Grant dateMar 29, 2005
Priority date
Expiry dateFeb 24, 2023

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F9/526
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Disclosed is a multiprocessor system including a semaphore register and a semaphore interrupt register. In addition, for each processor in the multiprocessor system, there is a semaphore interrupt enable register. If a first processor finds that a semaphore cell of the semaphore register holds a “1” indicating that an associated shared resource is being accessed by a second processor, the first processor sets a corresponding semaphore interrupt enable cell of the semaphore interrupt enable register to “1” so as to enable semaphore interrupt. When the second processor finishes with the shared resource, the second processor writes a 0 into the semaphore cell, causing a corresponding semaphore interrupt cell of the semaphore interrupt register to hold a “1”. This, combined with the fact that the semaphore interrupt enable cell also holds a “1”, causes an interrupt to the first processor. In response, the first processor services the interrupt and accesses the shared resource. As a result, repetitive reading and writing the semaphore cell by the first processor via a system bus of the multiprocessor system can be avoided.

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