초록 ▼

A digital system has a resource, such as a communication bus, adapted for access by a plurality of devices, a plurality of devices adapted to access the resource, and an arbitrator for arbitrating access to the resource by the devices. The arbitrator includes a programmable memory comprising a plura

A digital system has a resource, such as a communication bus, adapted for access by a plurality of devices, a plurality of devices adapted to access the resource, and an arbitrator for arbitrating access to the resource by the devices. The arbitrator includes a programmable memory comprising a plurality of addressable words and an address generator for cyclically sequentially addressing each of the memory words. Each word stores information defining a priority order of the devices for accessing the resource. In particular, each word is divided into a plurality of segments, and each segment corresponds with a priority level in the order of priority. Each segment holds information identifying the device currently having the corresponding priority level. The priority order is changeable by reprogramming the contents of the memory. The priority order so implemented may be any conceivable order, and in particular may include a constant decreasing priority, a round-robin priority, or a combination of the two. A selecting arrangement responsive to the requesting devices and to the contents of the currently addressed memory word selects the highest priority requesting device for access to the resource, and an access granting arrangement grants to the selected device access to the resource.

대표청구항 ▼

A digital system comprising: (A) a resource; (B) a plurality of devices coupled to the resource for accessing the resource; and (C) means coupled to the devices for controlling access by the devices to the resources, the controlling means including a programmable memory means comprising addressable

A digital system comprising: (A) a resource; (B) a plurality of devices coupled to the resource for accessing the resource; and (C) means coupled to the devices for controlling access by the devices to the resources, the controlling means including a programmable memory means comprising addressable locations, each of said addressable locations comprising a plurality of storage means, each storage means of an addressable location permanently corresponding with a unique priority level different from priority levels of the other storage means at that same location, and each storage means of each addressable location for storing information identifying the device having the corresponding level of priority; addressing means coupled to the memory means for cyclically addressing each addressable location to retrieve from the addressed location the information stored by the storage means thereof; and means coupled to the memory means and to the plurality of devices and responsive to the information stored in the plurality of storage means of an addressed location for selecting a device for access to the resource.