Martin Dusek

Kinetis K20 - unable to debug

Discussion created by Martin Dusek on Aug 30, 2012
Latest reply on Nov 21, 2012 by Martin Nichols

Hello,

my setup:

 

Kinetis K20 MK20DX256ZVLQ10 on my own board - only JTAG connector + MCU + 3.3V regulator, nothing else. There ale pull ups on RESET_b and NMI_b pins

Rowley CrossStudio for ARM v 2.2

Rowley CrossConnect Lite JTAG adapter

 

I'm unable to connect to target, I get "Cannot find debug component from ROM Table" or timeout error message when trying to connect.

 

I can see MCU restarts itself every 50us (square wave with T = 50 us on RESET_b pin) and it doesn't matter whether JTAG adapter is or is not connected to MCU.

 

JTAG adapter is working fine with another MCU (NXP LPC2138).

 

Please can you help?

 

Martin

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