CAN Module Wake-Up Bypass Unit for Reduced Latency
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Solution Overview
Problem
Existing CAN systems face challenges in reducing wake-up time and energy consumption due to the sequential wake-up of CAN controllers and transceivers, which limits their ability to quickly transition from a sleep state to an operation state.
Innovation Solution
The proposed CAN module incorporates a wake-up unit and a bypass unit to simultaneously control the CAN controller and the CAN transceiver, allowing them to wake up in parallel by sending a predefined wake-up pattern through the TXD interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the CAN controller and CAN transceiver wake up sequentially (traditional method), then the system structure remains simple, but the wake-up time is extended and energy consumption increases
Solution Approach 1:
The system is segmented into three functional units: a wake-up unit, a CAN controller, and a bypass unit. The bypass unit operates independently during wake-up to send wake-up patterns to the transceiver, while the CAN controller handles normal CAN communication. This segmentation allows parallel wake-up operations without requiring complex coordination between components.
Solution Approach 2:
The bypass unit acts as an intermediary component that temporarily takes over the TXD interface to send wake-up patterns to the transceiver. This intermediary approach allows the transceiver to wake up in parallel with the CAN controller without requiring the CAN controller to be fully operational first, thus reducing total wake-up time while maintaining simple system architecture.
2Use of energy by moving object
If the CAN components remain in sleep state for longer periods to save energy, then energy consumption is reduced, but the wake-up response time increases
Solution Approach 1:
The bypass unit is pre-configured to send wake-up patterns through the TXD interface as soon as a wake-up event is detected. This preliminary action ensures that the transceiver begins its wake-up process immediately in parallel with the CAN controller, minimizing the time both components need to remain in sleep state while maintaining low energy consumption.
Solution Approach 2:
The system uses periodic wake-up patterns (dominant-recessive bit sequences) sent by the bypass unit to reliably wake up the transceiver. These periodic signals ensure robust wake-up detection while allowing the system to remain in low-power sleep mode for extended periods between communications, optimizing the balance between energy savings and response speed.
Data Source
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AI summary
The present invention relates to a Controller Area Network, CAN, module comprising: a first transmit data, TXD, interface, a first receive data, RXD, interface, a CAN controller, a wake-up unit, and a bypass unit, wherein the CAN controller is coupled to the first TXD interface and to the first RXD interface, wherein the bypass unit is coupled to the first TXD interface, wherein the CAN controller is configured only in an operation state to send a CAN frame to a CAN transceiver via the first TXD interface, wherein the wake-up unit is configured to control the CAN controller such that the CAN controller changes from a sleep state to the operation state, wherein the bypass unit is configured to send a predefined bit pattern, referred to as a wake-up pattern, to the CAN transceiver via the first TXD interface, and wherein the wake-up unit is configured to control the bypass unit so that the bypass unit sends the wake-up pattern via the first TXD interface.