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JTAG Daisy Chain Debug configuration problem when a node is missing or changes.


I have a question regarding how to automatically point to a specific device in a JTAG daisy chain.

My HW configuration is as follows. Let’s say four types of cards, each one with a single microcontroller.

I am always going to have a single board for each type in my setup.



Debugger/programmer: Segger J-Link

uC: STM32H7

My problem is, I need to have a fixed configuration in my STM32 Cube Ide Debug configuration so I can point to the type of board I want to program/debug.

This would be an easy one if all the boards are always present and powered. But let’s consider the following cases:


CASE 1: I need to debug Device type C but Device type B is not present.  




Although my HW has ways to bypass the device and keep the loop alive, I’d need to recalculate the tap number and IDpre of Device C.


CASE 2: I need to reach Device B for debugging/programming, but I replaced it with another different board. (other SN, other uC, different IDCODE).



So, I am looking for the kind of solution in which I can identify the board by type, not by IDCODE.

Also, I need to find a solution for the CubeIDE to look for the board type using a script before deciding the JTAG parameters it’s going to use for debug.

Any help will be much appreciated.