Computer architecture and system for efficient management of bi-directional bus
AssigneeHewlett-Packard Development Company, L.P.
InventorsMaurice B. Steinman, Richard E. Kessler, Gregg A. Bouchard
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Abstract
An efficient system and method for managing reads and writes on a bi-directional bus to optimize bus performance while avoiding bus contention and avoiding read/write starvation. In particular, by intelligently managing reads and writes on a bi-directional bus, bus latency can be reduced while still ensuring no bus contention or read/write starvation. This is accomplished by utilizing bus streaming control logic, separate queues for reads and writes, and a simple 2 to 1 mux.
Claims13
A system for managing bidirectional bus usage, comprising:
- a bidirectional bus;
- a read queue for pending read bus transactions;
- a write queue for pending write bus transactions;
- a mux having a first input coupled to said read queue and a second input coupled to said write queue and an output coupled to said bus;
- bus streaming control logic coupled to said read queue and said write queue having at least one control signal coupled to said mux;
- and
- wherein said bus streaming control logic selects for issuance to the bus either read transactions from said read queue or write transactions from said write queue to reduce the number of transitions between read transactions and write transactions.
A method, comprising:
- tracking the number of pending writes in a write queue;
- tracking the number of pending reads in a read queue;
- tracking the number of consecutively issued reads when the number of pending writes reaches a pending write threshold;
- tracking the number of consecutively issued writes when the number of pending reads reaches a pending read threshold;
- transitioning from issuance of reads to issuance of writes when the number of pending writes reaches said pending write threshold and the number of consecutively issued reads reaches a consecutively issued read threshold;
- and
- transitioning from issuance of writes to issuance of reads when the number of pending reads reaches said pending read threshold and the number of consecutively issued writes reaches a consecutively issued write threshold.
A system, comprising:
- a bus;
- a read queue configured to contain pending read transactions;
- a write queue configured to contain pending write transactions;
- and
- control logic configured to select for issuance to the bus either read transactions from said read queue or write transactions from said write queue to reduce the number of transitions between read transactions and write transactions.
Dependencies are inferred from the claim text.