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STM32F4Discovery entering debug requires holding reset

sc2
Associate II
Posted on March 29, 2014 at 20:01

I have been working with an STM32F0Discovery Board where entering debug mode simply requires pressing the ''Make & Restart Debugger'' (green arrow) button in IAR. 

With the STM32F4 discovery board, the STLink will not identify the target MCU unless I hold down the reset button until the ''starting debugger session'' pop-up appears. Then, upon releasing the reset button, the debugger proceeds to download to flash and enter debug mode. This seems like strange behavior to me. Is this normal?
1 REPLY 1
Posted on March 29, 2014 at 21:39

More likely the user code is causing the SWD/JTAG interface to be inaccessible. Perhaps WFI loops, DMA, etc.  If you strap BOOT0 to VDD does is still act like this?

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