US5557755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for improving bus utilization efficiency
Assignee: Apple Inc
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Filing: 1994-02-24
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Granted: 1996-09-17
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Expires: 2014-02-24
Abstract
Abstract In a bus system including a bus, a plurality of nodes including a primary node, and a bus access coordinator, bus utilization efficiency is improved by operating the coordinator at the same clock frequency as the primary node. The primary node is the node in the bus system which accesses the bus most frequently. By running the coordinator synchronous with the primary node, the need for synchronization events between the two components is eliminated. Since the primary node accesses the bus most frequently, eliminating synchronization events with the primary node eliminates most of the synchronization events in the bus system. Thus, synchronization events are minimized which, in turn, improves bus utilization efficiency.
Inventors
- 👤 William T. Krein
- 👤 Charles M. Flaig
- 👤 James D. Kelly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:59
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/38; G06F13/40; G06F13/4004; G06F13/4022
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
166 words
In a system comprising a bus, a plurality of nodes, each node receiving a clock signal, the nodes coupled to the bus, and a bus coordinator coupled to the nodes for coordinating access to the bus by the nodes, a method for operating the system, comprising the steps of: determining which node accesses the bus most frequently; designating from one of the plurality of nodes a primary node as the node in the system that accesses the bus most frequently, the primary node receiving the clock signal for the primary node; deriving an operating clock signal from the clock signal received by the primary node; operating the primary node in response to the operating clock signal; and applying the operating clock signal to the bus coordinator to operate the bus coordinator at the same clock signal as the primary node, thereby ensuring synchronous operation between the primary node and the bus coordinator, each other node operating in response to the clock signal received by that node.
Claim 2
Dependent Claim
166 words
In a system comprising a bus, a plurality of nodes, each node receiving a clock signal, the nodes coupled to the bus, and a bus coordinator coupled to the nodes for coordinating access to the bus by the nodes, a method for operating the system, comprising the steps of: determining which node accesses the bus most frequently; designating from one of the plurality of nodes a primary node as the node in the system that accesses the bus most frequently, the primary node receiving the clock signal for the primary node; deriving an operating clock signal from the clock signal received by the primary node; operating the primary node in response to the operating clock signal; and applying the operating clock signal to the bus coordinator to operate the bus coordinator at the same clock signal as the primary node, thereby ensuring synchronous operation between the primary node and the bus coordinator, each other node operating in response to the clock signal received by that node.
Claim 3
Dependent Claim
27 words
The method of the system in claim 1, wherein the determining step further comprises the step of implementing an arbitration protocol based on a round-robin fairness scheme.
Claim 4
Dependent Claim
128 words
A bus system, comprising: a bus; a plurality of nodes, each node receiving a clock signal, coupled to the bus, one of the plurality of nodes being a primary node designated as the node that is determined to access the bus most frequently, the primary node deriving an operating clock signal from the clock signal received by the primary node and operating in response to the operating clock signal; and a bus coordinator coupled to the nodes for coordinating access to the bus by the nodes, the bus coordinator receiving the operating clock signal and operating in response to the operating clock signal, ensuring synchronous operation between the primary node and the bus coordinator, each other node operating in response to the clock signal received by that node.
Claim 5
Dependent Claim
128 words
A bus system, comprising: a bus; a plurality of nodes, each node receiving a clock signal, coupled to the bus, one of the plurality of nodes being a primary node designated as the node that is determined to access the bus most frequently, the primary node deriving an operating clock signal from the clock signal received by the primary node and operating in response to the operating clock signal; and a bus coordinator coupled to the nodes for coordinating access to the bus by the nodes, the bus coordinator receiving the operating clock signal and operating in response to the operating clock signal, ensuring synchronous operation between the primary node and the bus coordinator, each other node operating in response to the clock signal received by that node.
Claim 6
Dependent Claim
15 words
The bus system in claim 3, wherein the primary node is a computer system board.
Claim 7
Dependent Claim
15 words
The bus system in claim 3, wherein the primary node is a computer data port.
Claim 8
Dependent Claim
15 words
The bus system in claim 3, wherein the primary node is a computer peripheral component.
Claim 9
Dependent Claim
23 words
The bus system in claim 3, wherein the operating clock signal is the same as the clock signal received by the primary node.
Claim 10
Dependent Claim
20 words
The bus system in claim 3, wherein the bus coordinator system selects the primary node from the plurality of nodes.
Claim 11
Dependent Claim
169 words
In a bus coordinator system comprising a bus, a plurality of nodes coupled to the bus, each node receiving a clock signal, and a bus coordinator coupled to the nodes for coordinating access to the bus by the nodes, a method for operating the bus coordinator system comprising the steps of: receiving at the bus coordinator a bus request signal from each node requiring bus access; determining which node accesses the bus most frequently; selecting one bus request signal of a node determined to access the bus most frequently; designating the node of the selected bus request signal as a primary node; sending a bus grant signal from the bus coordinator to the primary node; deriving an operating clock signal from the clock signal received by the primary node; operating the primary node in response to the operating clock signal, each other node functioning in response to the clock signal received by that node; and applying the operating clock signal to the bus coordinator to operate the bus coordinator.
Claim 12
Dependent Claim
169 words
In a bus coordinator system comprising a bus, a plurality of nodes coupled to the bus, each node receiving a clock signal, and a bus coordinator coupled to the nodes for coordinating access to the bus by the nodes, a method for operating the bus coordinator system comprising the steps of: receiving at the bus coordinator a bus request signal from each node requiring bus access; determining which node accesses the bus most frequently; selecting one bus request signal of a node determined to access the bus most frequently; designating the node of the selected bus request signal as a primary node; sending a bus grant signal from the bus coordinator to the primary node; deriving an operating clock signal from the clock signal received by the primary node; operating the primary node in response to the operating clock signal, each other node functioning in response to the clock signal received by that node; and applying the operating clock signal to the bus coordinator to operate the bus coordinator.
Claim 13
Dependent Claim
30 words
The method of operating the bus coordinator system in claim 9, wherein the determining step further comprises the step of implementing an arbitration protocol based on a round-robin fairness scheme.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-09-17 | 2000-03-18 | 2000-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-17 | 2004-03-18 | 2004-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-17 | 2008-03-18 | 2008-09-17 | $7700.00 | Window Closed / Lapsed |