BCM Wake-Up Control Using Pin State Polling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The limited number of pins with wake-up functions in Micro Controller Units (MCUs) in Body Control Modules (BCMs) restricts the number of external wake-up sources that can be supported, necessitating chip replacement and inflexible power management during hibernation.
Innovation Solution
A wake-up control method and device that allocates hardware pins more flexibly by writing IDs and wake-up level information to a retention RAM, using a wake-up detection timer to enable power supply only when necessary, and disabling it if conditions are not met, allowing normal input pins to serve as wake-up sources and enabling flexible power control during low power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of pins with wake-up function in MCU is limited, then the chip selection requirements are reduced, but the number of external wake-up sources that can be supported is insufficient
Solution Approach 1:
The patent makes all MCU pins capable of serving as wake-up sources by enabling power supply to all pins during hibernation and detecting wake-up signals through software polling of pin states. This transforms the system from having dedicated wake-up pins to having universal wake-up capability across all pins, allowing any pin to function as a wake-up source without requiring special hardware wake-up functionality.
2Adaptability or versatility
If power supply is enabled to all MCU pins during hibernation, then any pin can serve as wake-up source, but power consumption increases
Solution Approach 1:
The patent implements periodic wake-up detection by setting a wake-up detection timer that periodically checks the states of all MCU pins during hibernation. Instead of continuously monitoring all pins, the system periodically samples pin states, reducing power consumption while maintaining the ability to detect wake-up signals from any pin. This transforms continuous monitoring into periodic sampling.
3Reliability
If hardware pins are used for wake-up function, then wake-up sources are reliable, but the output state of pins cannot be flexibly controlled during hibernation
Solution Approach 1:
The patent dynamically configures pin functions and states based on runtime conditions. During hibernation, all pins are enabled for potential wake-up detection, and the system dynamically determines which pins are actually needed based on periodic detection. The output states of pins can be dynamically adjusted based on detected wake-up conditions, transforming static pin configuration into dynamic adaptability.
Data Source
AI summary
A wake-up control method for a Body Control Module (BCM) includes: step S1 writing IDs and wake-up level information of all Micro Controller Unit (MCU) pins serving as an external wake-up source to a retention RAM; step S2, setting a wake-up detection timer, and triggering a system to enter a low power consumption mode; step S3, after a wake-up detection time set by the wake-up detection timer expires, enabling power supply to all MCU pins, setting the corresponding MCU pin as an input pin according to the pin ID information written in step S1, and acquiring level information of the input pin; and step S4, comparing the level information of the input pin with the wake-up level information written in step S1, if they are consistent, writing the ID of the input pin that is to serve as a wake-up source to the retention RAM and triggering the system to enter a normal operating mode, and if they are inconsistent, disabling the power supply to the MCU pin. A wake-up control device for a BCM is further provided. The wake-up control method and the wake-up control device for a BCM reduce selection requirements for MCU chips, and provide more flexible hardware pin allocation and design for a wake-up source.