We are using STM32L151VCT6A-ND IC in devices; where I observed that in some of the ICs pin PA13 (JTMS-SWDIO) is low and not able to detect the MCU. Could anyone please help me to solve this issue.
To enable this pin you can follow this thread:
"Can not connect to target" using ST link utility
I was not able to connect to the ST-Link; "No target connected" Error message is displaying.
Pin PA13 (JTMS-SWDIO) is low. Is it possible to make it pull-high?
Even I have tried making pin PA13 pull-up externally..
Have you tried to enter DFU - I mean embedded bootloader firmware where the SWD pin is enabled?
Yes, Tried to upgrade firmware; but it failed.By default itself SWD pin is low ( might be disabled)
Is this custom board? Was it working before? Is the ST-link works with another board? Cable replaced?
The link above assumed that the problem is wrongly programmed MCU (prohibited certain pins) - it happens often when you generate code through CubeMX.
No, it was not working before. Changed the cable and checked.
With the same design we have done almost 150 boards in that nearly 20 boards(MCU) are not working.
ST-link works for other boards.
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