ESP32 Forum

Posted: **Sun Dec 21, 2025 1:36 am**

Hi!

Are there any limitations to programming the ESP32C3 (ESP32-C3-WROOM) only using the JTAG pins from ESP-Prog-2?

So far I have not yet made it work with openocd, with the following command:

Code: Select all

idf.py openocd --openocd-commands="-f interface/esp_usb_bridge.cfg -f target/esp32c3.cfg"

I have control over the enable and boot pins from another processor on the custom board.

Posted: **Mon Dec 22, 2025 11:00 am**

I think I have found the answer to my question, from https://docs.espressif.com/projects/esp ... -jtag.html

By default, ESP32-C3 JTAG interface is connected to the built-in USB_SERIAL_JTAG peripheral. To use an external JTAG adapter instead, you need to switch the JTAG interface to the GPIO pins. This can be done by burning eFuses using idf.py tool.

Burning DIS_USB_JTAG eFuse will permanently disable the connection between USB_SERIAL_JTAG and the JTAG port of the ESP32-C3. JTAG interface can then be connected to GPIO4-GPIO7. Note that USB CDC functionality of USB_SERIAL_JTAG will still be usable, i.e., flashing and monitoring over USB CDC will still work.

Posted: **Tue Dec 23, 2025 1:01 pm**

Please check if the target file esp32c3.cfg is missing.

ESP32 Forum

Program ESP32C3 with only JTAG pins from ESP-Prog-2?

Program ESP32C3 with only JTAG pins from ESP-Prog-2?

Re: Program ESP32C3 with only JTAG pins from ESP-Prog-2?

Re: Program ESP32C3 with only JTAG pins from ESP-Prog-2?