1. An arbitrator comprising: an array of arbitration vectors, each arbitration vector including a group of first bits, each first bit corresponding to request information for each of a number of devices, where each first bit indicates that the request information is pending or that the request information is not pending; an aggregate arbitration vector including a plurality of second bits, each second bit corresponding to one of the arbitration vectors; a circuit associated with each arbitration vector-second bit pair to set values for the second bits when a first bit in the arbitration vectors of the arbitration vector-second bit pair indicates that request information is pending for the corresponding device; a pointer register to store pointers that reference the set values for the second bits; and an arbitration component to arbitrate services among the number of devices based on the set values in the aggregate arbitration vector as referenced by a corresponding one of the stored pointers.