Hi all,
I'm in the process of bringing up a new board with an nRF5340 and am seeing some strange behavior. Via JLink SWD, I am able to connect to the application core on the nRF5340 as below:
SEGGER J-Link Commander V6.98e (Compiled Mar 29 2021 14:18:50) DLL version V6.98e, compiled Mar 29 2021 14:18:44 Connecting to J-Link via USB...O.K. Firmware: J-Link V11 compiled Feb 4 2021 12:59:17 Hardware version: V11.00 S/N: 51011401 License(s): GDB VTref=1.790V Type "connect" to establish a target connection, '?' for help J-Link>connect Please specify device / core. <Default>: CORTEX-M33 Type '?' for selection dialog Device> Please specify target interface: J) JTAG (Default) S) SWD T) cJTAG TIF>s Specify target interface speed [kHz]. <Default>: 4000 kHz Speed> Device "CORTEX-M33" selected. Connecting to target via SWD Found SW-DP with ID 0x6BA02477 DPIDR: 0x6BA02477 Scanning AP map to find all available APs AP[4]: Stopped AP scan as end of AP map has been reached AP[0]: AHB-AP (IDR: 0x84770001) AP[1]: AHB-AP (IDR: 0x84770001) AP[2]: JTAG-AP (IDR: 0x12880000) AP[3]: JTAG-AP (IDR: 0x12880000) Iterating through AP map to find AHB-AP to use AP[0]: Core found AP[0]: AHB-AP ROM base: 0xE00FE000 CPUID register: 0x410FD214. Implementer code: 0x41 (ARM) Found Cortex-M33 r0p4, Little endian. FPUnit: 0 code (BP) slots and 0 literal slots Security extension: not implemented CoreSight components: ROMTbl[0] @ E00FE000 Cortex-M33 identified. J-Link>
However, if I attempt to flash, the process fails due to read back protection and, when I attempt to recover, that process fails. I've attached a log from the attempted recovery to this ticket as well.
The device is currently powered via VBUS/VDDH, as shown in the schematic screenshot below.
Any advice or suggestions on useful next debug steps would be much appreciated. Thanks!
