Round robin bus arbitration with control vectors and increment and decrement functions

Abstract

Techniques for round robin bus arbitration are disclosed. A plurality of bus requesters is coupled to a common bus by an arbitration logic. Bus access requests are stored in a request vector (RV). A grant history vector (GHV) that contains the last granted requester is checked. A relative request vector (RRV) is created by performing N circular shifts in a right direction until the last granted requester occupies a first bit position in the RRV. The RRV is examined for the first asserted bit beginning with a second bit position in the first direction. A one-hot encoded relative grant vector (RGV) is generated based on the first asserted bit in the RRV. A grant vector (GV) is produced by executing N circular shifts of the RGV in a left direction. Access is granted to the bus requester indicated by the GV.