PROGRAMMABLE BUS ARBITER INCLUDING REAL TIME PRIORITY INDICATOR FIELDS FOR ARBITRATION PRIORITY SELECTION

摘要

A programmable bus arbiter is provided that includes a plurality of arbitration priority registers each having a real time field for arbitration priority selection. Each real time bus master is associated with a designated real time field within the bus arbiter. Each real time field includes a real time access bit indicative of whether a real time access is to be initiated by the associated master and a priority code which sets the arbitration priority for the master with respect to other masters which may contend for the bus. Prior to initiating a real time data transfer, the real time field for a particular master may be programmed to indicate the real time transfer as well as to set the priority level for the request. A bus arbitration state machine detects the real time fields and grants bus mastership to real time bus agents in favor of other contending bus requests by non-real time agents.