Weighted bus arbitration based on transfer direction and consumed bandwidth

Abstract

A bus arbitration algorithm precisely controls the relative bus channel bandwidth allocated to each master device by considering the direction of, and / or the bus channel bandwidth consumed by, a bus transaction. At least one weighting register is associated with each master device; in one embodiment, one weighting register per bus channel. The register is periodically loaded with a proportionate share of the available bus bandwidth. Upon being granted a bus transaction on a bus channel, the corresponding weighting register is decremented by an amount that reflects the bus channel bandwidth consumed by the transaction, measured in amount of data transferred or number of bus data transfer cycles required to complete the transaction. In the case of equal initial allocation of relative bandwidth share, master devices that consume bus channel bandwidth will have relatively low priority; master devices that do not consume bus channel bandwidth retain relatively high priority.

Description

technical field The present invention relates generally to the field of processors, and more particularly to a bus arbitration method that considers data transfer direction and bus channel bandwidth consumption. Background technique Portable electronic devices continue to increase in complexity and computing power, providing users with increasing functionality. Modern portable electronic devices may include: wireless data and voice communications; photography and video capture and playback; location determination and geographic routing; gaming with complex graphics; high-fidelity audio reception and playback; In the near future, portable electronic devices are expected to support ubiquitous ad hoc data communications (eg, IEEE 802.11, Bluetooth, and the like), virtual reality user interfaces, and many other advances. In many cases, this diverse functionality is implemented with one or more main processors plus dedicated processing circuitry. For example, a graphics coproce...

AI Technical Summary

Problems solved by technology

Since the above arbitration algorithm takes into account which channel the master is using, its arbitration weighting scheme does not accurately reflect the actual bus bandwidth consumption of the master

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