Processor Resource Latency Reduction via Hardware Notification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional portable computing devices face significant delays and power inefficiencies when processors transition between sleep and active states due to the need for software handshakes, which are slow and prone to interrupt service and context switch problems, especially when managing shared resources across multiple subsystems.
Innovation Solution
A method and system that manage resource state transitions by scheduling the process to begin at a specific time, allowing it to be completed just in time for the processor to enter the new state, thereby minimizing resource latency and eliminating the need for software handshakes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If software handshakes are used to coordinate resource state transitions between multiple SOC subsystems, then resource coordination reliability is improved, but transition time and power consumption increase significantly
Solution Approach 1:
The patent replaces software-based handshake protocols with a hardware-based notification mechanism. The controller directly notifies the processor of resource state changes through hardware signals, eliminating the need for software interrupt service routines and context switches. This substitution of mechanical/software systems with hardware systems dramatically reduces transition time while maintaining coordination reliability.
Solution Approach 2:
The controller performs resource state transitions in advance and notifies the processor before the processor needs to enter or exit sleep state. By completing resource coordination beforehand and using hardware notifications to signal readiness, the system eliminates waiting time during state transitions while ensuring all resources are properly coordinated.
2Reliability
If software handshakes are used to manage shared resource states, then resource state coordination is achieved, but processor power savings are reduced due to extended active state duration
Solution Approach 1:
The hardware notification mechanism allows the processor to enter sleep state immediately upon receiving the hardware signal, without remaining active to complete software handshake protocols. This reduces the duration of high-power processor operation while maintaining reliable resource coordination through the hardware-based notification system.
Solution Approach 2:
The controller completes all resource state transitions and coordination in advance before notifying the processor. This allows the processor to enter sleep state as soon as possible, maximizing power savings while ensuring all shared resources are properly coordinated through the preliminary hardware-based resource management.
3Reliability
If synchronous software handshakes are used before processor sleep state entry, then resource shutdown coordination is achieved, but transition speed and system responsiveness deteriorate
Solution Approach 1:
The patent replaces synchronous software handshake protocols with asynchronous hardware notification signals. The controller can notify the processor of resource state changes immediately through hardware signals without waiting for software processing, dramatically increasing state transition speed while maintaining coordination reliability through the hardware notification mechanism.
4Adaptability or versatility
If software handshakes are implemented for resource coordination, then shared resource management is achieved, but system complexity and susceptibility to interrupt delays increase
Solution Approach 1:
The hardware notification mechanism eliminates complex software handshake protocols, interrupt service routines, and context switch management. The hardware system inherently handles the coordination logic through dedicated notification signals, reducing software complexity and susceptibility to interrupt-related delays while maintaining full shared resource management capability.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Resource state sets corresponding to the application states are maintained in memory. A request may be issued for a processor operating in a first application state corresponding to the first resource state set to transition to a second application state corresponding to the second resource state set. A start time to begin transitioning resources to states indicated in the second resource state set is scheduled based upon an estimated amount of processing time to complete transitioning. A process is begun by which the states of resources are switched from states indicated by the first resource state set to states indicated by the second resource state set. Scheduling the process to begin at a time that allows the process to be completed just in time for the resource states to be immediately available to the processor upon entering the second application state helps minimize adverse effects of resource latency.