Clock Management Circuit for Staged Processor Wake-Up
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Solution Overview
Problem
High-speed processor circuits experience instantaneous current peaks and supply voltage drops due to clock gating transitions, leading to unexpected behavior and potential circuit failures, which existing solutions like adding capacitors on the printed circuit board increase costs.
Innovation Solution
A clock management circuit and method that includes a delay circuit and clock control circuit to manage the operating clock by delaying wake-up interrupts and gradually adjusting frequency, mitigating current surges by transitioning processor circuits from idle to active states at varying clock frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If clock gating is used to reduce power consumption in idle state, then power consumption is reduced, but instantaneous current peaks occur during wake-up causing supply voltage drops
Solution Approach 1:
The delay circuit delays the wake-up interrupt signal before it reaches the clock control circuit, allowing the system to prepare gradually for wake-up. This preliminary delay prevents sudden current peaks by staging the clock frequency restoration process, thus maintaining supply voltage stability while still enabling power savings from clock gating.
Solution Approach 2:
The clock control circuit dynamically adjusts the clock frequency in multiple stages based on the delayed wake-up interrupt. Instead of immediately restoring full clock frequency, the system transitions through intermediate frequency levels, which smooths the current draw and prevents instantaneous current peaks that would cause voltage drops.
2Reliability
If a capacitor is added on the printed circuit board to stabilize supply voltage, then supply voltage stability is improved, but manufacturing cost increases
Solution Approach 1:
The invention extracts the voltage stabilization function from the external capacitor (which would be added on the PCB) and implements it internally through the delay circuit and clock control circuit. By managing clock frequency transitions internally, the system achieves voltage stability without requiring additional external components, thus reducing manufacturing cost while maintaining reliability.
Solution Approach 2:
The delay circuit acts as an intermediary between the wake-up interrupt and the clock control circuit, mediating the transition process. This intermediary component enables gradual clock frequency restoration that stabilizes supply voltage internally, replacing the need for external capacitor-based voltage stabilization and reducing overall system cost.
3Productivity
If clock frequency is immediately restored upon wake-up, then productivity is improved, but current surges cause supply voltage drops
Solution Approach 1:
The delay circuit provides a preliminary delay to the wake-up interrupt, allowing the clock control circuit to initiate frequency restoration in a controlled manner. This preliminary action enables productivity improvement by starting the wake-up process promptly while preventing harmful current surges through staged frequency increases.
Solution Approach 2:
The clock control circuit employs dynamic frequency adjustment, transitioning the clock frequency from idle to active state in multiple stages rather than instantly. This dynamic approach maintains productivity by enabling quick wake-up while ensuring supply voltage stability through controlled current draw at each frequency transition level.
Data Source
AI summary
A clock management circuit and a clock management method are used for managing an operating clock of a processor circuit, and the processor circuit changes the level of a state signal according to an interrupt signal. The clock management circuit includes a delay circuit for delaying a wake-up interrupt to generate a delayed wake-up interrupt; and a clock control circuit for generating the operating clock according to a reference clock, generating the wake-up interrupt according to the state signal, and adjusting the frequency of the operating clock according to the delayed wake-up interrupt.