Memory Bandwidth Allocation With Round-Robin Bonus Arbitration

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Solution Overview

Problem

In communication environments with limited bandwidth, efficiently allocating bandwidth among multiple applications while ensuring fair access and preventing interference, particularly in safety-critical systems like automotive systems, is challenging, as existing methods often lead to delays and imbalanced resource utilization.

Innovation Solution

Implementing a freedom from interference (FFI) arbitration scheme with a round-robin approach and bonus count mechanism to allocate bandwidth dynamically among different groups, ensuring no single application dominates and maintaining low latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single application dominates bandwidth usage, then that application achieves high bandwidth utilization, but other applications cannot access bandwidth when needed

Engineering Contradiction:
Improvebandwidth utilizationVSAvoidfair access guarantee
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments bandwidth allocation into multiple arbitration groups, where each group can be independently controlled. This segmentation prevents a single application from dominating all bandwidth by dividing the arbitration space into separate controllable units, ensuring that no single group can monopolize the shared resource.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent dynamically changes arbitration parameters (such as group identifiers and allocation ratios) based on system conditions. By adjusting these parameters, the system can prevent any single application from consistently dominating bandwidth while ensuring fair access is maintained across different applications.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If arbitration waits to assess other potential masters before granting access, then bandwidth allocation fairness is improved, but access latency increases

Engineering Contradiction:
Improvebandwidth allocation fairnessVSAvoidaccess latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs preliminary arbitration assessments by maintaining information about potential masters and their access patterns in advance. This preliminary action allows the arbitration logic to make faster decisions without waiting to fully assess all conditions at the moment of access request, thereby reducing latency while maintaining fairness.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The arbitration mechanism uses self-service principles where the system maintains its own state information about applications and bandwidth usage. This self-knowledge allows for quicker arbitration decisions without requiring extensive external assessment, reducing access latency while ensuring fair allocation.

Inventive Principle:
Principle #25Self-service

3Productivity

If limited bandwidth is shared among multiple applications, then resource efficiency is improved, but ensuring each application gets needed bandwidth becomes challenging

Engineering Contradiction:
Improveresource efficiencyVSAvoidbandwidth allocation control
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent implements feedback mechanisms that monitor bandwidth usage and application needs in real-time. This feedback information is used to dynamically adjust arbitration decisions, ensuring that each application receives appropriate bandwidth while maintaining overall resource efficiency. The feedback loop enables the system to respond to changing conditions without manual intervention.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4361826B1Bandwidth allocation
Publication Date: 2025.09.10 NXP BV
  • EP4361826B1 patent drawingFigure 1
  • EP4361826B1 patent drawingFigure 2A
  • EP4361826B1 patent drawingFigure 2B

AI summary

Aspects of the disclosure are directed to allocating bandwidth. As may be implemented in accordance with one or more embodiments, respective amounts of bandwidth are allocated to respective application groups for each memory access cycle in a set of memory access cycles. Initial bonus bandwidth is provided to a first one of the application groups during one of the memory access cycles. The bonus bandwidth may include at least a portion of bandwidth allocated to and unused by one of the other respective application groups during the memory access cycle. Additional bonus bandwidth is selectively provided to the first application group during one of the memory access cycles based on the initial bonus bandwidth and a maximum amount of bonus bandwidth defined for the set of memory access cycles, in response to bandwidth allocated to one of the other respective application groups during the subsequent memory access cycle being unused.