Patent ID: 7162557

Claim:
A competition arbitration system comprising: a predetermined resource (bus 33 ); N devices ( 30 - 1 , . . . , 30 -N) to competitively use the predetermined resource; an arbitrating apparatus ( 40 ) for arbitrating the N devices to use the predetermined resource; and N control means (bus masters 32 ) that are associated respectively with the N devices; (a) wherein the arbitrating apparatus includes N gate circuits ( 60 - 1 , . . . , 60 -N) that are associated respectively with the N devices, a pulse generating circuit ( 50 ) which generates, during a period (T), N pulses (grant pulse GP- 1 , . . . , GP-N) corresponding respectively to the N devices, and sequentially outputs the N pulses to respective ones of the N gate circuits, and an inhibiting circuit ( 55 ) which, while any one of the N devices is using the predetermined resource, inhibits others of the devices, not using the predetermined resource, from acquiring the predetermined resource for use; (b) wherein each control means outputs a request signal (RQ) to a corresponding one of the gate circuits when one of the devices corresponding thereto needs to use the predetermined resource; receives a grant signal (GR-i, i=1, . . . ,N) from the corresponding gate circuit for controlling the corresponding device to use the predetermined resource; and outputs an acknowledgment signal (AK-i, i=1, . . . , N) to the inhibiting circuit during a time interval in which the corresponding device uses the predetermined resource; and (c) wherein, the inhibiting circuit, while receiving the acknowledgment signal (AK-i) from any of the control means, outputs an inhibition signal (IG) to all of the gate circuits, and each gate circuit, when simultaneously receiving the corresponding request signal (RQ) outputted from the corresponding control means and the corresponding pulses (GP) outputted from the pulse generating circuit but not receiving the inhibition signal (IG), outputs the corresponding grant signal (GR-i, i=1, . . . , N) to the control means; and (d) wherein the system does not use fixed priorities.