Thank you kindly for your reply,  I’ve added the nRF52840 line in the mcu.csv and the device is now being properly recognized by the debugger.

My line in the MCU.csv file looks like this:

Nordic Semi;nRF52840_xxAA;nRF52840_xxAA internal;0E0000FF;0;0;0;4BA00477;0;20000000;8000

I believe 0x4BA00477 is the Cortex-M4 core type id, 0x20000000 is the SRAM start, but I’m not too sure about 0x0E0000FF though, I just copied it from nRF52832, and I don’t really know what it represents, I could not find anything at that location by just looking at the nRF52832 memory map or within the nRF52832 documentation.

Still, going back to the nRF52840, no matter which example I run for the nRF52840, I always get the same error: Exception Thrown, received a SIGTRAP…

The call stack always points to the same area:

0x000208fe ; <UNDEFINED> instruction: 0xffffffff

I am using the nRF52840 Preview Development Kit (DK) board PCA10056.

Any other suggestions are greatly appreciated.

Thank you!

Thank you for your reply.

It does that with any program. Please download my Blinki demo and try it out.

Inside the folder you will also find a screenshot.png file with the error I get. The program never runs on the dev board, breakpoints are not executed. Please also note that the dev board is perfectly fine when programmed in other ways (hex directly to JLink, IAR compiler, etc.). I just cannot get it to program right with VSGDB.

Many thanks!

Thank you very much for your reply, the SDK I used with IAR is nRF5_SDK_14.0.0_3bcc1f7.

I took the nRF52840_Blinki.bin file generated by VSGDB and dropped it in the JLINK drive. The file was properly programmed and worked like a charm, so that means it was properly compiled and linked. The issue I’m having is that I cannot properly program the board using VSGDB and Segger, and that makes me think this is not an SDK issue, but rather a JLINK driver problem or a MCU.CSV definition problem.

I have already talked about the exact line I embedded in the MCU.csv file and you had no comments, which makes me think my mcu definition line was correct.

Next, I am using JLink_V616a, is this the same version you have tested my sample program with?

Thanks again for all the help!

I will try that next, but just as an FYI, I have tried to Program and Start Without Debugging and it failed to program the device: Debugging Failed: Failed to program 6 out of 6 sections.

GDB Log:

C:\SysGCC\arm-eabi\bin\arm-eabi-gdb.exe –interpreter mi C:\nRF_VSGDB\Blinky_2\VisualGDB\Debug\Blinky_2
-gdb-version
=thread-group-added,id=”i1″
~”GNU gdb (GDB) 7.12\n”
~”Copyright (C) 2016 Free Software Foundation, Inc.\n”
~”License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html&gt;\nThis is free software: you are free to change and redistribute it.\nThere is NO WARRANTY, to the extent permitted by law. Type \”show copying\”\nand \”show warranty\” for details.\n”
~”This GDB was configured as \”–host=i686-pc-mingw32 –target=arm-eabi\”.\nType \”show configuration\” for configuration details.”
~”\nFor bug reporting instructions, please see:\n”
~”<http://www.gnu.org/software/gdb/bugs/&gt;.\n”
~”Find the GDB manual and other documentation resources online at:\n<http://www.gnu.org/software/gdb/documentation/&gt;.\n”
~”For help, type \”help\”.\n”
~”Type \”apropos word\” to search for commands related to \”word\”…\n”
~”Reading symbols from C:\\nRF_VSGDB\\Blinky_2\\VisualGDB\\Debug\\Blinky_2…”
~”done.\n”
~”GNU gdb (GDB) 7.12\n”
~”Copyright (C) 2016 Free Software Foundation, Inc.\n”
~”License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html&gt;\nThis is free software: you are free to change and redistribute it.\nThere is NO WARRANTY, to the extent permitted by law. Type \”show copying\”\nand \”show warranty\” for details.\n”
~”This GDB was configured as \”–host=i686-pc-mingw32 –target=arm-eabi\”.\nType \”show configuration\” for configuration details.”
~”\nFor bug reporting instructions, please see:\n”
~”<http://www.gnu.org/software/gdb/bugs/&gt;.\n”
~”Find the GDB manual and other documentation resources online at:\n<http://www.gnu.org/software/gdb/documentation/&gt;.\n”
~”For help, type \”help\”.\n”
~”Type \”apropos word\” to search for commands related to \”word\”.\n”
^done
-list-features
^done,features=[“frozen-varobjs”,”pending-breakpoints”,”thread-info”,”data-read-memory-bytes”,”breakpoint-notifications”,”ada-task-info”,”language-option”,”info-gdb-mi-command”,”undefined-command-error-code”,”exec-run-start-option”]
-gdb-set disassembly-flavor intel
^error,msg=”No symbol \”disassembly\” in current context.”
-gdb-set print demangle off
^done
-break-insert -f main
^done,bkpt={number=”1″,type=”breakpoint”,disp=”keep”,enabled=”y”,addr=”0x0002246e”,func=”main()”,file=”LEDBlink.cpp”,fullname=”C:\\nRF_VSGDB\\Blinky_2\\Blinky_2\\LEDBlink.cpp”,line=”20″,thread-groups=[“i1″],times=”0″,original-location=”main”}
target remote :51547
&”target remote :51547\n”
~”Remote debugging using :51547\n”
=thread-group-started,id=”i1″,pid=”42000″
=thread-created,id=”1″,group-id=”i1″
~”0x0002098e in ?? ()\n”
*stopped,frame={addr=”0x0002098e”,func=”??”,args=[]},thread-id=”1″,stopped-threads=”all”
^done
info shared
&”info shared\n”
~”No shared libraries loaded at this time.\n”
^done
mon reset
&”mon reset\n”
@”Resetting target\r\n”
^done
load
&”load\n”
~”Loading section .softdevice, size 0x22000 lma 0x0\n”
+download,{section=”.softdevice”,section-size=”139264″,total-size=”254555″}
~”Loading section .isr_vector, size 0x200 lma 0x22000\n”
+download,{section=”.isr_vector”,section-size=”512″,total-size=”254555″}
~”Loading section .text, size 0x163c lma 0x22200\n”
+download,{section=”.text”,section-size=”5692″,total-size=”254555″}
~”Loading section .init_array, size 0x4 lma 0x2383c\n”
+download,{section=”.init_array”,section-size=”4″,total-size=”254555″}
~”Loading section .fini_array, size 0x4 lma 0x23840\n”
+download,{section=”.fini_array”,section-size=”4″,total-size=”254555″}
~”Loading section .data, size 0x4 lma 0x23844\n”
+download,{section=”.data”,section-size=”4″,total-size=”254555″}
~”Start address 0x22b50, load size 145480\n”
~”Transfer rate: 14207 KB/sec, 10391 bytes/write.\n”
^done
mon reset
&”mon reset\n”
@”Resetting target\r\n”
^done
compare-sections
&”compare-sections\n”
~”Section .softdevice, range 0x0 — 0x22000: MIS-MATCHED!\n”
~”Section .isr_vector, range 0x22000 — 0x22200: MIS-MATCHED!\n”
~”Section .text, range 0x22200 — 0x2383c: MIS-MATCHED!\n”
~”Section .init_array, range 0x2383c — 0x23840: MIS-MATCHED!\n”
~”Section .fini_array, range 0x23840 — 0x23844: MIS-MATCHED!\n”
~”Section .data, range 0x23844 — 0x23848: MIS-MATCHED!\n”
&”warning: One or more sections of the target image does not match\nthe loaded file\n”
&”\n”
^done

GDB Server Log:

C:\Program Files (x86)\SEGGER\JLink_V616a\JLinkGDBServerCL.exe -select USB -device nRF52840_XXAA -speed auto -if SWD -port 51547
SEGGER J-Link GDB Server V6.16a Command Line Version

JLinkARM.dll V6.16a (DLL compiled Jun 6 2017 12:42:51)

—–GDB Server start settings—–
GDBInit file: none
GDB Server Listening port: 51547
SWO raw output listening port: 2332
Terminal I/O port: 2333
Accept remote connection: localhost only
Generate logfile: off
Verify download: off
Init regs on start: off
Silent mode: off
Single run mode: off
Target connection timeout: 0 ms
——J-Link related settings——
J-Link Host interface: USB
J-Link script: none
J-Link settings file: none
——Target related settings——
Target device: nRF52840_XXAA
Target interface: SWD
Target interface speed: auto
Target endian: little

Connecting to J-Link…
J-Link is connected.
Firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Mar 2 2017 12:22:13
Hardware: V1.00
S/N: 683669353
Checking target voltage…
Target voltage: 3.30 V
Listening on TCP/IP port 51547
Connecting to target…Connected to target
Waiting for GDB connection…Connected to 127.0.0.1
Reading all registers
Read 2 bytes @ address 0x0002246E (Data = 0xFFFF)
Read 2 bytes @ address 0x0002246E (Data = 0xFFFF)
Read 2 bytes @ address 0x0002246E (Data = 0xFFFF)
Read 4 bytes @ address 0x0002098E (Data = 0xF44FE7FD)
Read 2 bytes @ address 0x0002098E (Data = 0xE7FD)
Resetting target
Downloading 16256 bytes @ address 0x00000000
Downloading 16240 bytes @ address 0x00003F80
Downloading 16208 bytes @ address 0x00007EF0
Downloading 16240 bytes @ address 0x0000BE40
Downloading 16208 bytes @ address 0x0000FDB0
Downloading 16256 bytes @ address 0x00013D00
Downloading 16208 bytes @ address 0x00017C80
Downloading 16160 bytes @ address 0x0001BBD0
Downloading 9488 bytes @ address 0x0001FAF0
Downloading 512 bytes @ address 0x00022000
Downloading 5692 bytes @ address 0x00022200
Downloading 4 bytes @ address 0x0002383C
Downloading 4 bytes @ address 0x00023840
Downloading 4 bytes @ address 0x00023844
Writing register (PC = 0x502b0200)
Read 2 bytes @ address 0x0002246E (Data = 0xFFFF)
Read 2 bytes @ address 0x0002246E (Data = 0xFFFF)
Read 2 bytes @ address 0x0002246E (Data = 0xFFFF)
Read 4 bytes @ address 0x00022B50 (Data = 0xFFFFFFFF)
Resetting target
Reading 1024 bytes @ address 0x00000000
Reading 1024 bytes @ address 0x00000400
Reading 1024 bytes @ address 0x00000800
Reading 1024 bytes @ address 0x00000C00
Reading 1024 bytes @ address 0x00001000
Reading 1024 bytes @ address 0x00001400
Reading 1024 bytes @ address 0x00001800
Reading 1024 bytes @ address 0x00001C00
Reading 1024 bytes @ address 0x00002000
Reading 1024 bytes @ address 0x00002400
Reading 1024 bytes @ address 0x00002800
Reading 1024 bytes @ address 0x00002C00
Reading 1024 bytes @ address 0x00003000
Reading 1024 bytes @ address 0x00003400
Reading 1024 bytes @ address 0x00003800
Reading 1024 bytes @ address 0x00003C00
Reading 1024 bytes @ address 0x00004000
Reading 1024 bytes @ address 0x00004400
Reading 1024 bytes @ address 0x00004800
Reading 1024 bytes @ address 0x00004C00
Reading 1024 bytes @ address 0x00005000
Reading 1024 bytes @ address 0x00005400
Reading 1024 bytes @ address 0x00005800
Reading 1024 bytes @ address 0x00005C00
Reading 1024 bytes @ address 0x00006000
Reading 1024 bytes @ address 0x00006400
Reading 1024 bytes @ address 0x00006800
Reading 1024 bytes @ address 0x00006C00
Reading 1024 bytes @ address 0x00007000
Reading 1024 bytes @ address 0x00007400
Reading 1024 bytes @ address 0x00007800
Reading 1024 bytes @ address 0x00007C00
Reading 1024 bytes @ address 0x00008000
Reading 1024 bytes @ address 0x00008400
Reading 1024 bytes @ address 0x00008800
Reading 1024 bytes @ address 0x00008C00
Reading 1024 bytes @ address 0x00009000
Reading 1024 bytes @ address 0x00009400
Reading 1024 bytes @ address 0x00009800
Reading 1024 bytes @ address 0x00009C00
Reading 1024 bytes @ address 0x0000A000
Reading 1024 bytes @ address 0x0000A400
Reading 1024 bytes @ address 0x0000A800
Reading 1024 bytes @ address 0x0000AC00
Reading 1024 bytes @ address 0x0000B000
Reading 1024 bytes @ address 0x0000B400
Reading 1024 bytes @ address 0x0000B800
Reading 1024 bytes @ address 0x0000BC00
Reading 1024 bytes @ address 0x0000C000
Reading 1024 bytes @ address 0x0000C400
Reading 1024 bytes @ address 0x0000C800
Reading 1024 bytes @ address 0x0000CC00
Reading 1024 bytes @ address 0x0000D000
Reading 1024 bytes @ address 0x0000D400
Reading 1024 bytes @ address 0x0000D800
Reading 1024 bytes @ address 0x0000DC00
Reading 1024 bytes @ address 0x0000E000
Reading 1024 bytes @ address 0x0000E400
Reading 1024 bytes @ address 0x0000E800
Reading 1024 bytes @ address 0x0000EC00
Reading 1024 bytes @ address 0x0000F000
Reading 1024 bytes @ address 0x0000F400
Reading 1024 bytes @ address 0x0000F800
Reading 1024 bytes @ address 0x0000FC00
Reading 1024 bytes @ address 0x00010000
Reading 1024 bytes @ address 0x00010400
Reading 1024 bytes @ address 0x00010800
Reading 1024 bytes @ address 0x00010C00
Reading 512 bytes @ address 0x00022000
Reading 1024 bytes @ address 0x00022200
Read 4 bytes @ address 0x0002383C (Data = 0xFFFFFFFF)
Read 4 bytes @ address 0x00023840 (Data = 0xFFFFFFFF)

Thanks!

Well, as I said before, I can program it with IAR, no problems. Also, if I take the .bin file generated by VSGDB and drop it in the J_Link virtual drive that pops-up automatically when you insert the USB cable, the board gets programed and functions just fines. Same with any other examples from the SDK: if dropped in the J-Link drive, all programs will work.  So to me at least, this does not look like a defective board, but rather a communication issue between GDB and J-Link.

I will try diferent ways of programming the board, see if I can learn anything else.

Thanks!