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What is the proper UART assignment for using printf with JTAG?

Question asked by dave408 on May 19, 2015
Latest reply on May 26, 2015 by dave408

I'm just getting started with KDS 3.0 and KSDK 1.2 and am in the process of recreating the work I've previously done with KDS 2.0 and KSDK 1.1.


I would like to be able to use debug_printf with the DbgCs1 component on a custom MK64FN1M0VLL12-based PCB.  I also want to communicate with other peripherals over RS485 or RS232.  I believe I have a problem with the routing, because the RS485 connection is routed to PTB16/PTB17, which is allocated to UART0.  Since JTAG is also connected to UART0, then I assume this means I'm going to have to re-route the signals, or just not use that port until the next rev.


So in short, I take it that the proper design methodology behind incorporating Kinetis processors is to first look at the UART that shares pins with the JTAG connections, and then prevent usage of this UART on any of the other pins that provide access to that peripheral?


In addition, when I select those pins in DbgCs1, I get a conflict with my CPU settings:



What is the right approach for supporting debug_printf over JTAG and JTAG if I'm getting conflicts in the PEx definitions?