AnsweredAssumed Answered

Problem flashing for the first time

Question asked by Buca Ze on Mar 3, 2016
Latest reply on Mar 4, 2016 by Kerry Zhou

Dear community,

 

in aspiration to lose the fog of my current ignorance, I appreciate any help to get back on track.

 

TL;DR

Can't get my Kinetis KL27 custom board to do anything.

No USB Enumeration / SWD (J-Link) detects secured device.

At POR RESETb gets pulled down internally after short strobe (~1ms). Could this be the watchdog in action?

 

Please let me guide you to my current setup.

 

board.png

 

Following some schematics. VDD = 3.3V.

mcu.jpg

swd.png

usb.jpg

Following the first Power-on, no USB-Enumeration happened. Examining closer the isolated MCU consumes 3mA @ 3.3V. Strangely RESETb is pulled low. As is the J-Link probes orange LED indicating.

 

J-Link command

> JLinkExe -if swd -device MKL27Z64XXX4 -speed 1000

followed by

>> connect

outputs

Device "MKL27Z64XXX4" selected.


Found SWD-DP with ID 0x0BC11477
Secured Kinetis device detected. For debugger connection the device needs to be unsecured.
Device will be unsecured now.
Note: Unsecuring will trigger a mass erase of the internal flash.
Found SWD-DP with ID 0x0BC11477
Secured Kinetis device detected. For debugger connection the device needs to be unsecured.
Device will be unsecured now.
Note: Unsecuring will trigger a mass erase of the internal flash.

****** Error: Kinetis (connect): Timeout while unsecuring device. Erase never starts.
Kinetis (connect): Failed to unsecure Kinetis device.

 

Please help me resolve this situation and uncover any design flaws. Any help is really appreciated.

Thank you in advance!

 

cheers,

Luca

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