(DEV_TARGET_RESET_ERR)

[dogukansahil]

 

Hello,
I’m trying to program my STM32 microcontroller STM32F301C8T6TR using ST-LINK, but I keep getting the "DEV_TARGET_RESET_ERR" error. Here’s what I’ve tried so far:

1. Reset Pin (NRST): Connected directly to the RST pin of the ST-LINK.
2. BOOT0 Pin: Connected to VCC during programming (with a 10k pull-up resistor).
3. Power Supply: The microcontroller is powered with 3.3V (measured voltage is 3.26V via ST-LINK).
4. SWDIO and SWCLK: Checked the connections with a multimeter, continuity is fine.
5. Firmware Update: Updated the ST-LINK firmware to the latest version (V2J45S7).
6. STM32CubeProgrammer: Tried "Connect Under Reset" and reduced SWD frequencies, but no luck.
7. External Reset Circuit: I’m not using any external reset circuits or chips.
8. Alternative Attempt: Added a 1k resistor to the NRST pin, but it didn’t solve the issue.

Despite all these steps, I’m unable to connect to the microcontroller. Has anyone encountered this problem before or has any suggestions?

As it happened before, I could write blink code in it once, but it always gave an error afterwards. I managed to delete it with full erase, but it always gives an error when adding new code.

[TDK]

Are you using a genuine programmer?

VDDA connected to VDD?

Is NRST high after chip has power?

[dogukansahil]

 

I bought the programmer cheaply, I'm not sure about its originality. I designed the STM32 board as a pcb. I have 10 cards and I could only program 1 of them only once. I couldn't even program the others at all.

During programming, I reset the programming pin and tried both connecting and not connecting it to the pin. (I connected the BOOT0 pin to VCC and fed the card with both 3.3 (without regulator) and 5v, the result is always the same.)

If everything is negative, I don't understand how I managed to program the first card once.

I am grateful for the help..

[TDK]

Is NRST high after the chip has power?

Schematic is fine, missing a few decoupling caps perhaps. Could be a bad programmer, or bad soldering, or bad connections between the board and programmer.

> If everything is negative, I don't understand how I managed to program the first card once.

Don't be fooled. Just because it works once doesn't mean it's right.

[dogukansahil]

I just connected the NRST pin to the RST pin of the programmer. I don't understand what you mean here, but I thought this was optional anyway.