초록 ▼

A round robin bus arbitrator that prevents bus starvation caused by an inbound buffer becoming full and forcing repetitive retries by an agent. The arbitrator performs a rotating scan of the request lines of multiple potential bus requesters. When a request is detected, the arbitrator stops, grants

A round robin bus arbitrator that prevents bus starvation caused by an inbound buffer becoming full and forcing repetitive retries by an agent. The arbitrator performs a rotating scan of the request lines of multiple potential bus requesters. When a request is detected, the arbitrator stops, grants the request, and resumes scanning after the requester takes control of the bus. If the data buffer on a write operation becomes full and cannot accept any more data, a signal so indicating is sent to the arbitrator. The arbitrator then stops scanning, or refuses to resume scanning if it is already stopped, until the buffer indicates it is no longer full. The next requester that is granted the bus is therefore not confronted with a full buffer, and not thereby forced to abort the request and make a retry. The invention avoids bus starvation caused by a second bus requestor repeatedly being given a retry response because the buffer is repeatedly filled up by an earlier bus requestor.

대표청구항 ▼

A round robin bus arbitrator that prevents bus starvation caused by an inbound buffer becoming full and forcing repetitive retries by an agent. The arbitrator performs a rotating scan of the request lines of multiple potential bus requesters. When a request is detected, the arbitrator stops, grants

A round robin bus arbitrator that prevents bus starvation caused by an inbound buffer becoming full and forcing repetitive retries by an agent. The arbitrator performs a rotating scan of the request lines of multiple potential bus requesters. When a request is detected, the arbitrator stops, grants the request, and resumes scanning after the requester takes control of the bus. If the data buffer on a write operation becomes full and cannot accept any more data, a signal so indicating is sent to the arbitrator. The arbitrator then stops scanning, or refuses to resume scanning if it is already stopped, until the buffer indicates it is no longer full. The next requester that is granted the bus is therefore not confronted with a full buffer, and not thereby forced to abort the request and make a retry. The invention avoids bus starvation caused by a second bus requestor repeatedly being given a retry response because the buffer is repeatedly filled up by an earlier bus requestor. said physical memory in advance of the delivery of said data storage area by said data delivery means. 11. A particular computer as defined in claim 10, wherein said memory-wire-down release means releases said wire-down of the data storage area in accordance with a designation of the area for which said wire-down on said physical memory is to be released, the designation being affixed to a message containing the data as transferred from said remote direct memory access means of said communicating opposite computer. 12. A particular computer as defined in claim 4, further comprising wire-down-area-capacity change request means for requesting the communicating opposite computer to change a capacity of an area which has been wired down on the physical memory of the communicating opposite computer beforehand, and in which the data to be transferred from said remote direct memory access means of said particular computer is stored. 13. A particular computer as defined in claim 12, wherein said wire-down-area-capacity change request means makes the request for changing the capacity of the area, in accordance with a quantity of the data which is to be transferred from said particular computer to the communicating opposite computer. 14. A particular computer as defined in claim 13, further comprising physical-memory-wire-down-area adjustment means for adjusting a capacity of an area which has been wired down on said physical memory of said particular computer beforehand, and in which the data to be transferred from said remote direct memory access means of said communicating opposite computer is stored, in compliance with the request for changing the capacity of the area as made by said wire-down-area-capacity change request means of said communicating opposite computer. 15. A particular computer as defined in claim 12, further comprising physical-memory-wire-down-area adjustment means for adjusting a capacity of an area which has been wired down on said physical memory of said particular computer beforehand; and in which the da