Simulink External Mode (Monitor & Tune) Timeout on Custom STM32H750VBTx Board via ST-LINK-V3
Hello STM Community,
I am facing an XCP protocol timeout when trying to use Simulink Monitor & Tune (External Mode) with a custom STM32H750VBTx board and an ST-LINK-V3 (COM10, 115200 baud).
The Setup & Symptoms:
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What works: Code generation and flashing complete successfully. "Build, Deploy and Start" works perfectly (e.g., standard LED blink routines run fine).
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What fails: Clicking "Connect" for External Mode immediately times out with:
XCP internal error: timeout expired, in response to XCP CONNECT command. -
Hardware verified: Standard UART communication has been tested separately on this custom board and works flawlessly at 115200 baud. No other software is locking the COM port.
Questions:
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Cache/MPU: Since this is an STM32H7, do the buffers used by the Simulink XCP serial stack require specific MPU or D-Cache configurations to prevent data coherency issues?
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Interrupt Conflict: Is there a known issue where the XCP background task gets starved by higher priority model execution steps on the H7?
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Peripherals: Are there specific pitfalls when mapping the XCP transport layer to a USART vs. LPUART instance in the Simulink Hardware pane?
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Which USART/UART to use for Monitor and Tune.
Any quick troubleshooting steps to get the XCP handshake responding would be highly appreciated.
