System and method for controlling bus access for bus agents having varying priorities
First Claim
1. A computer system comprising:
- a bus;
an arbitration unit coupled to said bus;
a plurality of bus agents coupled to said bus, said plurality of bus agents including one or more high-priority bus agents and one or more normal-priority bus agents, and wherein said arbitration unit is configured to cause a termination of mastership of said bus by one of said normal-priority bus agents responsive to receiving a bus access request from one of said high-priority bus agents; and
a first bus interface unit coupled to said arbitration unit, wherein said arbitration unit is configured to assert a bus disconnect signal responsive to a bus access request from a high-priority bus agent, wherein said bus disconnect signal is received by said bus interface unit.
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Accused Products
Abstract
A system and method for bus arbitration. A computer system includes one or more buses for transferring data. Access to each bus is controlled by an arbitration unit. Various bus agents (i.e. peripherals) are coupled to the bus. Some bus agents are designated as normal-priority agents, while other bus agents are designated as high-priority bus agents. A high-priority bus agent may be a peripheral that is a latency-sensitive device. The arbitration unit may grant bus access to a normal-priority bus agent based on an arbitration scheme. When a high-priority bus agent requests access to the bus, the arbitration unit may cause the termination of access by the normal-priority bus agent. The high-priority bus agent is then granted access to the bus. When the high-priority bus agent has completed its use of the bus, the arbitration unit allows the normal-priority bus agent to regain access to the bus.
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Citations
17 Claims
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1. A computer system comprising:
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a bus;
an arbitration unit coupled to said bus;
a plurality of bus agents coupled to said bus, said plurality of bus agents including one or more high-priority bus agents and one or more normal-priority bus agents, and wherein said arbitration unit is configured to cause a termination of mastership of said bus by one of said normal-priority bus agents responsive to receiving a bus access request from one of said high-priority bus agents; and
a first bus interface unit coupled to said arbitration unit, wherein said arbitration unit is configured to assert a bus disconnect signal responsive to a bus access request from a high-priority bus agent, wherein said bus disconnect signal is received by said bus interface unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of operating a computer system, the method comprising:
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granting access to a bus for a normal-priority bus agent;
granting access to said bus for a high-priority bus agent responsive to a request for access by said high-priority bus agent, wherein access to said bus by said normal-priority bus agent is terminated responsive to said request for access by said high-priority bus agent;
controlling access to said bus by an arbitration unit; and
asserting a disconnect signal responsive to a request for bus access by said high-priority bus agent, said asserting performed by said arbitration unit. - View Dependent Claims (13, 14, 15, 16, 17)
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Specification