Thursday, August 9, 2012

Kinetis TWR-K70 main board mod for external debugger with trace

When plugging TWR main board to USB the integrated debugger enumerates and wants to install drivers. This can be annoying when you use external debugger and don't have drivers for on-board debugger installed at all. This debugger can be disabled with jumper connecting pins 2 and 4 on BDM connector J14. But with this change only the power switch for the rest of the board is permanently switched off. It can be forced to on state with applying high level on pin 4 of U2. Supply voltage is available on BDM connector.

Trace clock signal for parallel trace needs to be connected to external debug connector via R137 which is not populated by default.