Adaptive Power Gating Using Current Monitoring and Slack Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional adaptive power control systems for digital circuits face limitations in reducing power consumption due to high power overhead, inability to control power at the block level, and inefficiency in responding to operational speed variations, especially in high-speed circuits.
Innovation Solution
A self-aware adaptive power control system utilizing a multi-mode power gating network, current monitoring translator, variable threshold comparator, and bi-directional shift register to dynamically control supply current and circuit speed, eliminating the need for delay matching circuits and minimizing power overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If conventional adaptive power control systems are used, then power consumption can be controlled, but power overhead is high and block-level power control capability is lost
Solution Approach 1:
The power gating network is divided into multiple independent power gating cells, each controlling a specific circuit block. This segmentation enables block-level power control where each cell can independently manage power to its associated block, providing fine-grained power control capability that was lost in conventional systems.
Solution Approach 2:
The power gating cells automatically adjust their control signals based on the operational state of their associated circuit blocks. The system monitors circuit activity and self-regulates power delivery without requiring external control, reducing the overhead of power management while maintaining effective power control at the block level.
2Speed
If delay matching circuits are used to determine circuit characteristics, then circuit speed can be monitored, but additional reference clocks are required and power overhead increases
Solution Approach 1:
The invention extracts the circuit state detection function from complex delay matching circuits and implements it through simple current monitoring. By removing the delay matching circuitry and reference clock requirements, the system achieves circuit speed monitoring with minimal power overhead while maintaining the capability to respond to speed variations.
Solution Approach 2:
The mechanical/electrical delay matching system is replaced with an electrical current monitoring system. Instead of using complex timing circuits and reference clocks to determine circuit characteristics, the invention uses current measurements to infer circuit operational state, significantly reducing power consumption while maintaining speed monitoring capability.
3Use of energy by stationary object
If conventional power gating cells are used, then static power can be saved in closed state, but dynamic power control capability is lost and only ON/OFF states are provided
Solution Approach 1:
The power gating cells are designed with dynamic control capability, allowing the control signal to vary continuously rather than being fixed at only ON/OFF states. This enables the system to dynamically adjust power delivery to match the actual operational requirements of circuit blocks, providing both static power savings and dynamic power control adaptability.
Solution Approach 2:
The invention changes the control parameter from binary (ON/OFF) to continuous voltage or current levels. By allowing the control signal to vary across a range of values, the power gating cells can provide fine-grained dynamic power control while maintaining the ability to save static power when circuits are not in use.
4Measurement precision
If adaptive voltage regulation with delay matching circuits is used, then circuit characteristics can be determined, but voltage safety margins must be added and power reduction effect is limited
Solution Approach 1:
The invention uses simple, low-cost current monitoring circuits instead of complex delay matching circuits with voltage safety margins. The current monitoring approach provides sufficient circuit characteristic detection without requiring expensive or power-intensive safety margin circuits, achieving better power reduction effects while maintaining measurement precision.
Data Source
AI summary
The present invention provides a self-aware power control system and a method for determining the circuit state. The self-aware adaptive power control architecture comprises of a multi-mode power gating network, a current monitoring translator, a variable threshold comparator, a slack detector, and a bi-directional shift register. The multi-mode power gating network controls the amount of supply current and hence the circuit speed. The power gating network can be composed of either N-type MOSFETs for virtual ground insertion or P-type MOSFETs for virtual supply insertion. The number of MOSFETs in the multi-mode power gating network can be configured according to the supply range and step difference of the supply current. Then, by monitoring the current characteristics drained by target circuit, the circuit state can be determined. No delay matching circuit is required. Together with other peripherals, the supply current can be down controlled to a minimum acceptable level. The circuit will use up all available slack. The smaller current implies lower power consumption as well. Furthermore, the present invention is capable of self adaptation to frequency change. To summarize, the present invention can make the circuit consume least power under various frequency achieving best power efficiency.