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Releasing JTDO/NJTRST from PB3/PB4 for GPIO use

Question asked by arwani.mahmoud on Sep 8, 2016
Latest reply on Sep 12, 2016 by Edje
Using a STM32L152RCT6 - currently testing software on 32L152CDISCOVERY board


I am trying to configure PB3 (JTDO) as an output GPIO, however I am not able to do so. 
The pin is always stuck at 1.471V (Vcc/2) Vcc= 2.95.

I removed SB101 the solder bridge which connected it to the ST-Link in an attempt to resolve the issue with no luck.
PB4 (NJTRST) is having a similar issue, however when a Bit_Reset is written to it by user it resets from ist original state (Pulled up - 2.9V)


RM0038 mentions
"For user software designs, note that:
 To release the debug pins, remember that they will first be configured wither in input-pull-up 
 (nTRST, TMS, TDI) or pull-down (TCK) or output tristate(TDO) for a certain duration after reset
 until the instant when the user software releases the pins.


 When debug pins (JTAG or SW or TRACE) are mapped, changing the corresponding IO pin
 configuration in the IOPORT controller has no effect.
"


How do I release these pins, PB3 and PB4. 


Couldn't find any example code or proper explanation. 
Any suggestions welcome!

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