I can't get to "connect" to the MCU using the J-Link Commander software (JLink.exe, Version:"V633f" ) despite having followed the Segger troubleshooting guide.
This is my J-Link Commander log:
SEGGER J-Link Commander V6.33f (Compiled Jun 13 2018 17:12:50) DLL version V6.33f, compiled Jun 13 2018 17:11:37 Connecting to J-Link via USB...O.K. Firmware: J-Link V10 compiled Jun 13 2018 16:23:32 Hardware version: V10.10 S/N: 260107390 License(s): FlashBP, GDB OEM: SEGGER-EDU VTref=3.315V Type "connect" to establish a target connection, '?' for help J-Link>connect Please specify device / core. <Default>: ATSAME54N20 Type '?' for selection dialog Device> Please specify target interface: J) JTAG (Default) S) SWD TIF>S Specify target interface speed [kHz]. <Default>: 4000 kHz Speed>100 Device "ATSAME54N20" selected. Connecting to target via SWD InitTarget() Secured Atmel SAMD device detected. For debugger connection the device needs to be unsecured. Note: Unsecuring will trigger a mass erase of the internal flash. Executing default behavior previously saved in the registry. Device will be unsecured now. Mass erase done! Mass erase done! Mass erase done! Mass erase done! Mass erase done! ... (and about 420 "Mass erase done!" afterwards) ... Mass erase done! Cannot connect to target. J-Link>
Sorry if any obvious information is missing, I'll edit my post accordingly if asked to do so!
- The prove and software does work with an Aruino Due (SAM3X8E) board.
- I haven't got any SAME54N20 based or similar Demo boards available.
- This is the SWD interface schematic:
- This is the SWD interface board layout:
- Poligons are shelved, but GND runs on the bottom layer of the 1.6mm thick two layered board, and 3.3V the top layer.
- The reset trace continuing "outside the picture" goes to the actual Reset switch and series resistor, without any nearby routed signals.
- The SWD header middle key faces the silkscreen adjacent line.
- When I press the board Reset button the Segger J-Link LED turns red and stays green the rest of the time.
- Each time a "Mass erase done!" message is displayed, the J-Link LED blinks in a red color with green color in between.
- I haven't got an oscilloscope.
- Has someone experienced a similar behaviour in the past and knows how to fix it?
- What troubleshooting recommendations can you suggest?