Spread Spectrum Clock Gating for EMI Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for reducing energy consumption in electronic circuits, such as processors, through clock signal gating result in predictable and repeatable spectral peaks in power consumption, leading to electromagnetic compatibility issues and increased requirements for on-chip voltage regulators.
Innovation Solution
A method involving the generation of a modified clock signal by selectively masking clock cycles using a sequence-controlled gating signal, which can be randomly or pseudo-randomly distributed, allowing for adaptive power management based on workload and operational modes, thereby reducing energy consumption while minimizing spectral spikes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If clock signal is temporarily switched off to reduce energy consumption, then power consumption is reduced, but electromagnetic interference occurs due to abrupt changes in energy consumption
Solution Approach 1:
The patent applies periodic action by using a spread spectrum clocking technique where clock cycles are selectively suppressed in a pseudorandom pattern rather than continuously or predictably. This creates a periodic yet distributed suppression pattern that reduces peak electromagnetic interference while maintaining average power reduction benefits
Solution Approach 2:
The patent implements dynamics by using a dynamic clock suppression mechanism controlled by a spread spectrum signal. The clock suppression ratio and timing are dynamically adjusted based on operational requirements, allowing the system to adapt between performance and power saving modes while distributing interference across frequency spectrum
2Use of energy by moving object
If clock cycles are selectively suppressed to reduce power consumption, then energy usage decreases, but spectral peaks in power consumption are created leading to electromagnetic compatibility issues
Solution Approach 1:
The patent applies asymmetry by using asymmetric clock suppression patterns generated through spread spectrum techniques. Instead of symmetric or periodic suppression patterns that create predictable spectral peaks, the asymmetric pseudorandom suppression distributes energy across a broader frequency spectrum, eliminating concentrated spectral peaks
Solution Approach 2:
The patent converts the harmful effect of clock suppression (which creates spectral peaks) into a beneficial spread spectrum signal. By intentionally introducing controlled pseudorandom variations in clock suppression, the system transforms concentrated electromagnetic interference into distributed low-level interference across a wider bandwidth, improving electromagnetic compatibility
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The invention relates to a method for supplying a clock for an electronic circuit (232). Said method includes a step of gating clock cycles of a clock signal (100) using a sequence-controlled gating signal (234) so as to obtain a modified clock signal (106), and a step of supplying the modified clock signal (106) as the clock for the electronic circuit (232).