Adaptive Voltage-Frequency Guardband Circuit for Voltage Droop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems face challenges in efficiently mitigating voltage droop in supply voltages to processor circuits, leading to potential malfunctions and increased power consumption due to the need for large guardbands to prevent timing violations, and the static droop threshold is not optimal for varying workloads.
Innovation Solution
A voltage-droop mitigation circuit that monitors supply voltage and adjusts the droop threshold dynamically based on the number of clock cycles or times droop mitigation is performed, allowing for reduced power consumption by lowering the supply voltage while maintaining optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large guardband is used to prevent timing violations during voltage droop, then circuit reliability is improved, but power consumption increases
Solution Approach 1:
The droop threshold is made dynamic rather than static. The performance monitor tracks the number of times voltage-droop mitigation is performed and adjusts the droop threshold accordingly. When mitigation is performed frequently, the threshold is increased to reduce false positives; when performed rarely, the threshold is decreased to improve detection sensitivity. This dynamic adjustment allows the system to maintain reliability while optimizing power consumption by avoiding unnecessary mitigation actions.
Solution Approach 2:
The system changes the droop threshold parameter based on operational conditions. By monitoring the frequency of mitigation events and adjusting the threshold parameter dynamically, the system adapts to varying workload conditions and voltage droop characteristics, achieving an optimal balance between reliability and power consumption without requiring a consistently large guardband.
2Device complexity
If a static droop threshold is used, then device complexity is reduced, but adaptability to varying workloads deteriorates
Solution Approach 1:
A performance monitor is introduced that tracks the number of times voltage-droop mitigation is performed and feeds this information back to adjust the droop threshold. This feedback mechanism enables the system to adapt to varying workload conditions automatically, improving adaptability without significantly increasing device complexity. The threshold adjustment is based on simple counting and comparison logic.
Solution Approach 2:
The system performs self-adjustment of the droop threshold based on its own operational statistics. The performance monitor autonomously tracks mitigation events and adjusts the threshold without external intervention, allowing the system to adapt to varying workloads while maintaining simple architecture. The adjustment logic is self-contained and requires minimal additional hardware.
3Reliability
If voltage-droop mitigation is performed frequently, then circuit reliability is improved, but productivity deteriorates due to reduced clock frequency
Solution Approach 1:
The droop threshold is dynamically adjusted based on the frequency of mitigation events. When mitigation is performed frequently, the threshold is increased to prevent excessive clock frequency reductions. This dynamic adaptation allows the system to maintain reliability by adjusting to the actual voltage droop characteristics of the current workload, rather than applying conservative mitigation too aggressively.
Solution Approach 2:
The system changes the droop threshold parameter based on observed mitigation frequency. By adjusting this critical parameter, the system optimizes the balance between reliability and productivity. The threshold modification allows the system to tolerate larger voltage droops under certain conditions, reducing the need for clock frequency reduction and thereby maintaining higher productivity while ensuring reliability.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
In certain aspects, a system comprises a voltage-droop mitigation circuit configured to monitor voltage droop in a supply voltage supplied to a circuit, and to perform voltage-droop mitigation for the circuit if the monitored voltage droop is equal to or greater than a droop threshold. In one aspect, the system also includes a performance monitor configured to track a number of clock cycles over which the voltage-droop mitigation circuit performs the voltage-droop mitigation within a time duration, and to adjust the droop threshold based on the number of clock cycles. In another aspect, the system also includes a performance monitor configured to track a number of times that the voltage-droop mitigation circuit performs the voltage-droop mitigation within a time duration, and to adjust the droop threshold based on the number of times that the voltage-droop mitigation circuit performs the voltage-droop mitigation within the time duration.