Partial Processor Reset in Mobile Devices Without Display Disruption

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Solution Overview

Problem

Mobile wireless communications devices often require a full reset, which can result in lengthy reboot times and undesirable display changes, such as flickering or blanking, due to the resetting of all integrated circuits, including the CPU and GPU.

Innovation Solution

A mobile wireless communications device and method that allows for a partial reset of the processor without resetting the GPU, using a power management circuit to maintain power to the GPU and processor during the reset, and a logic circuit to control the reset signals, preventing display disruptions by keeping the GPU reset signal high.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a full reset operation is performed on all integrated circuits, then the software error is resolved, but the reboot time becomes lengthy and display disruptions occur

Engineering Contradiction:
Improvesoftware error resolutionVSAvoidreboot time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The reset operation is segmented into selective resetting of only the CPU rather than all integrated circuits. The power management circuit enables independent control of power supply to different ICs, allowing the CPU to be reset while the GPU and other circuits remain operational, thereby reducing reboot time from a full system reset to a partial reset duration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by providing different reset states to different parts of the system. The CPU undergoes reset while the GPU maintains its operational state through continuous power supply. This localized reset approach resolves the software error in the CPU without subjecting the entire system to a lengthy reboot cycle.

Inventive Principle:
Principle #3Local quality

2Reliability

If a full reset operation is performed on all integrated circuits, then the software error is resolved, but display disruptions such as flickering or blanking occur

Engineering Contradiction:
Improvesoftware error resolutionVSAvoiddisplay disruptions
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system is segmented into resettable and non-resettable components during error recovery. The CPU is isolated as the target for reset operations, while the GPU is excluded from the reset cycle through selective power management. This segmentation prevents the GPU from entering a disrupted state that would cause display flickering or blanking.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The power management circuit acts as an intermediary between the reset command and the integrated circuits. It receives the reset signal and selectively applies power cycling only to the CPU, while maintaining continuous power to the GPU. This intermediary control prevents the propagation of reset-induced disruptions to the display system.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the power supply is removed for a battery pull reset, then the system is fully reset, but the procedure is inconvenient for the user

Engineering Contradiction:
Improvesystem resetVSAvoidreset procedure convenience
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system performs self-service reset operations through software-initiated CPU reset commands executed by the processor itself or system software. This eliminates the need for user intervention to remove the battery or manipulate physical reset switches, making the reset procedure convenient and automated while still achieving reliable error recovery.

Inventive Principle:
Principle #25Self-service

4Loss of time

If a partial reset of the CPU is performed without resetting the GPU, then the reboot time is reduced, but the processor output pins return to default values which may adversely affect other subsystems

Engineering Contradiction:
Improvereboot timeVSAvoidsubsystem stability
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent applies local quality by providing different power states to different components. The CPU receives interrupted power supply during reset, while the GPU maintains continuous power supply to preserve its operational state and output values. This selective power management prevents the propagation of default value resets to subsystems driven by the GPU, such as the display.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2290494B1Mobile wireless communications device with reset function and related methods
Publication Date: 2020.04.29 BLACKBERRY LTD
  • EP2290494B1 patent drawingFigure 1
  • EP2290494B1 patent drawingFigure 2
  • EP2290494B1 patent drawingFigure 3~4

AI summary

A mobile wireless communications device may include a display, a graphics processing unit (GPU) being resettable and causing a change in the display when reset, a wireless transceiver, and a processor cooperating with the GPU and the wireless transceiver for wireless communications. The processor may be resettable along with the GPU, and the processor also may be partially resettable without resetting the GPU to avoid a change in the display.