AnsweredAssumed Answered

Jlink could not halt CPU during linking STM32F103VET6

Question asked by KUHAN JON on Sep 9, 2017
Latest reply on Sep 10, 2017 by Vangelis Fortounas


I have a trouble using STM32F103VET6.

I attached the reset and boot circuitary.

i have assembled three boards and tested.

Unfortunately, one of them was normal, but the others were not.

The trouble is as follows.

When i turned on the board, KEIL showed me "Auto write protected device detected........." and i clicked "yes" to download the firmware.

But the board did not work normally.

I measured the voltage of NRST pin and BOOT0 pin after power on. The voltage of the NRST pin was 3.34V( power supply voltage is 3.29V) and of the BOOT0 is 1.7V.

But the voltages of normal board were 3.28V and 0.1V respectively.

I tried agian to link Jlink( i used SW 4-wire mode), but KEIL warned "Jlink warning: CPU coild not be halted".

But the normal board always works normally.

I really did not analyze this phenomenon. 

Help me to find the reason of this trouble.

Thanks. Jon