Patent · US Expired

Asynchronous priority select logic

US5051986A · kind A · utility

13Cited by
3References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 1, 1989
Grant dateSep 24, 1991
Priority date
Expiry dateDec 1, 2009

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L12/433
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

The present invention provides asynchronous priority select logic for allowinig an individual station on a token ring network to hold a token for asynchronous transmission only for a specified maximum time period. The asynchronous priority select logic comprises a token rotation timer for timing token rotations on the ring from arrival to arrival. A token holding timer limits the amount of ring bandwidth used by the station for asynchronous transmission after the token is captured by the station. Select circuitry responsive to the value of the token rotation timer determines if the captured token is still usable for transmission by determining if the token rotation timer value is less than a preselected asynchronous threshold value. The select logic includes means for generating a selected asynchronous threshold value having a first bit length. The selected asynchronous threshold value is then expanded to a second bit length corresponding to the bit length of the token holding timer value. The expanded asynchronous threshold value and the token holding timer value are then compared and an output signal is asserted if the expanded selected asynchronous threshold value is greater tha…

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