Solution for No Cortex-M Device Found in JTAG Chain

Today I flashed a firmware, and it ran normally. However, when I tried to flash another firmware, I encountered this issue: No Cortex-M Device found in JTAG chain.Please check the JTAG cable and the connected devices.

I found the answer on Baidu, which indicated that treating the JTAG pins as I/O pins would cause the original JTAG functionality to fail.

Here is the solution that successfully resolved the issue:

1. Locate BOOT1 and BOOT0, pull BOOT1 low, and pull BOOT0 high to 3.3V.

2. Redownload the program and erase the FLASH.

3. Pull BOOT0 back low to its original state, and that’s it!

Solution for No Cortex-M Device Found in JTAG Chain

I also found another version of the problem: “No Cortex-M Device found in JTAG chain” or “Emulator has been changed or re-enumerated!”

Cause: The programmed firmware disabled the JTAG functionality and reused the JTAG interface, which prevented JTAG from working properly. In this case, you need to use a serial port to download a program that does not disable JTAG, and then you can use JTAG normally again.

The causes are the same, but the solutions differ. The first method is more convenient in comparison.

Solution for No Cortex-M Device Found in JTAG Chain

Related posts

  1. Comparison of Embedded Debug Interfaces JTAG and SWD
  2. Introduction to JTAG Testing Protocol
  3. Understanding JTAG and Other Debug Interfaces
  4. Analysis of ARM Cortex-M Core Reset Boot Process
  5. How to Make PCB Design More Artistic?
  6. Exploring the Applications of Xilinx ZYNQ-7000 Platform
  7. Summary of ARM Processor Classifications
  8. Application of Highbo Easy Arm™ Intelligent Lifting Device in Automotive Driveshaft Manufacturing
  9. Building Industrial IoT with CANopen Protocol
  10. Embedded Security Tool: Practical JTAG Debugging
  11. Understanding SWD Download Protocol for Cortex-M
  12. Introduction to JTAG Interface in Embedded C Development
  13. Debugging Protocol SWD as a Replacement for JTAG on ARM Architecture
  14. Understanding the JTAG Protocol for ECU Debugging
  15. JTAG Interface Hardware Design for STM32
  16. Understanding ARM Cortex-M Debugging and Tracing Techniques
  17. MCU Testing and External NOR Programming Using JTAG_BSDL – LPC1857 Example
  18. Interface Standard JTAG in Embedded Debugging
  19. Controlling JTAG with Raspberry Pi for Hardware Learning

Leave a Comment