Segger J-Link Commander debugger

Segger web page wiki

These notes based on version 6.87b 11/13/20

/Applications/SEGGER/JLink/JLinkExe \
-Device NRF52832_XXAA -Autoconnect 1 -if SWD -Speed 4000

... (sample startup)

To show output from source calls to NRF_LOG_…,
in another window start:

/Applications/SEGGER/JLink/JLinkRTTClient  

Waits for connection to J-Link

or
telnet localhost 19021
(permits entering commands for NRF_LOG_BACKEND_FLASH_CLI_CMDS)

-AutoConnect [0|1]
-Device example :NRF52832_XXAA
-If JTAG | SWD
-Speed example 4000
-CommanderScript,
-CommandFile
-JLinkScriptFile special connection sequence before communication with the core
-USB serialNumber
-SettingsFile file
-IP addr Example -IP 192.168.1.17
-RTTTelnetPort port
-ExitOnError
-SelectEmuBySN
-JTAGConf IRPre|DRPre example: -JTAGConf 4,1
-Log file

Connect via USB. connect [ usb [ 0 | 1 | 2 | 3 ] ]

Asks for DEVICE (suggests last used, ex NRF52832_XXAA)
target interface (like SWD)

Mode-Of-Entry, i.e.
Reason CPU halted 		moe
CPU halted because DBGRQ was asserted.          CPU halted due to vector catch.
halt | go h | g NumSteps   [0̸|1]
Simulate NumSteps   0̸ Do not start if a BreakPoint is within NumSteps 1: Overstep BPs
After halt, WatchDog timer WILL expire during halt and WDOG_HANDLER will be invoked after entering g

halt 

PC = 00000000, CycleCnt = 00000001
R0 = EFBFEB40, R1 = 00007FFE, R2 = 6D09E1BD, R3 = 00007FFF
R4 = 00000005, R5 = 00000000, R6 = 00000005, R7 = 00000000
R8 = 00446E80, R9 = 00000001, R10= 00446E80, R11= 00000001
R12= EFBFEB60
SP(R13)= 00007FFE, MSP= 6D09D4C7, PSP= 00007FFF, R14(LR) = 00000004
XPSR = 00000005: APSR = nzcvq, EPSR = EFBFEB90, IPSR = 01E (INTISR15)
CFBP = 6CF9E5B9, CONTROL = 00, FAULTMASK = 40, BASEPRI = 00, PRIMASK = 505AB0

FPS0 = EFBFEB40, FPS1 = 00007FFE, FPS2 = 6D09E1BD, FPS3 = 00007FFF
FPS4 = 00000005, FPS5 = 00000000, FPS6 = 00000005, FPS7 = 00000000
FPS8 = 00446E80, FPS9 = 00000001, FPS10= 00446E80, FPS11= 00000001
FPS12= EFBFEB60, FPS13= 00007FFE, FPS14= 6D09D4C7, FPS15= 00007FFF
FPS16= 00000004, FPS17= 00000000, FPS18= 00000005, FPS19= 00000000
FPS20= EFBFEB90, FPS21= 00007FFE, FPS22= 6CF9E5B9, FPS23= 00007FFF
FPS24= 00400CC0, FPS25= 00000001, FPS26= 00505AB0, FPS27= 00000001
FPS28= EFBFED40, FPS29= 00007FFE, FPS30= 00446E80, FPS31= 00000001
FPSCR= EFBFEBC0
WARNING: CPU could not be halted
Perhaps device is not connected or powered.
Registers Regs
Write register. wreg RegName, Value
wreg R9,0xD66
R9 = 0x00000D66
read memory
write memory

    layout 

mem[8|16|32|64][Zone:]Addr[,ngroups(in hex)  
w1|w2|w4|w4 [Zone:]Addr[ xData …]
Zone Name of memory zone to access. 
w4 10001080 01020304

mem32 10001080 4
10001080 = 01020304

mem 10001080 4
10001080 = 04 03 02 01 gawk!

mem16 10001080 2
10001080 = 0304 0102 (64 int16s) 



w1 10001080 FF
Writing FF -> 10001080
mem32 10001080 1
10001080 = 010203FF         GAWK!

w1 10001081 FE
Writing FE -> 10001081
mem 10001080 4
10001080 = FF FE 02 01
mem32 10001080 1
10001080 = 0102FEFF         GAWK!!

w4 10001081 0a0b0c0d
Writing 0A0B0C0D -> 10001081
Mis-aligned memory write: Address: 0x10001081, NumBytes: 4, Alignment: 4 (Word-aligned)
mem32 10001080 4
10001080 = 0B0C0D03 FFFFFF0A FFFFFFFF F401F401 
mem 10001080 16
10001080 = 03 0D 0C 0B 0A FF FF FF  FF FF FF FF 01 F4 01 F4  ................



Get the address of a static global from the map.
 grep -A1 vbat ruuvitag_b/s132/armgcc/_build/ruuvi_firmware.map |\
         sed "s/0x00000000\(........\)/mem16 \1,1/; s/        0x2//"
 .bss.vbat      mem16 20004486,1 _build/ruuvi_firmware_main.c.o

mem16 20004486,1
20004486 = ADC  
 Use:   echo 'ibase=16;ADC' |bc  to see 2780 millivolts)



 mem32 1f000,40 Interrupt Service Routine table 
0001F000 = 20010000 0003172D 00031755 00031757 
0001F010 = 00031759 0003175B 0003175D 00000000 
0001F020 = 00000000 00000000 00000000 0003175F 
0001F030 = 00031761 00000000 00031763 00031765 
0001F040 = 0002B451 00031767 00031767 0002BFD5 
0001F050 = 00031767 00031101 0002B889 0002C3E5 
0001F060 = 0002C06D 0002C135 0002C1FD 00031767 
0001F070 = 00031767 0002BB51 00031767 00031767 
0001F080 = 00023E95 00030005 00031767 00031767 
0001F090 = 000300C9 00031767 0003165D 00031767 
0001F0A0 = 00031767 00031767 0002C2C5 00030E45 
0001F0B0 = 00031767 00031767 00000000 00000000 
0001F0C0 = 00031767 00031767 00031767 00031767 
0001F0D0 = 0002BC2D 00031767 00031767 00000000 
0001F0E0 = 00000000 00000000 00000000 00000000 
0001F0F0 = 00000000 00000000 00000000 00000000 

mem64 2000,4  (4 64bit quad(?)words) 
00002000 = D0032D1278A5BBBC E7B8DFFFD0042D13 
00002010 = F7FFE001FF6FF7FF F006D1B12800FF55 



w4 10001080 00010203 04050607                     NRF_UICR->CUSTOMER
Writing 00010203 -> 10001080
Writing 04050607 -> 10001084

mem32 10001080,20
10001080 = 00010203 04050607 FFFF0908 FFFFFFFF 
10001090 = FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF 
…
100010FF = FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF 



Fill stack with C0FFEE:

w4 2000FA00 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FA40 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FA80 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FAC0 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FB00 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FB40 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FB80 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FBC0 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FC00 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FC40 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FC80 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FCC0 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FD00 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FD40 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FD80 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FDC0 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FE00 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FE40 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FE80 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FEC0 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FF00 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE
w4 2000FF40 C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE C0FFEE



Display stack: 

mem32 2000FC00,100      or less      mem32 2000FF00,40 

2000FF00 = 3A50D29F 00961AFE 00001903 0A040A02 
2000FF10 = 75755209 61316976 00003639 00000000 
2000FF20 = 00000006 00021E03 20002D9C 00000000 
2000FF30 = 20002DAC 00000AF3 00000060 A801BE00 
2000FF40 = 00000001 80000000 00000000 FFFFFFF9 
2000FF50 = 00000614 21000018 01000001 40020518 
2000FF60 = 00000001 80000000 00000000 00012639 
2000FF70 = 0001263A 21000000 50000000 00020000 
2000FF80 = 00080000 00003AFE 000000FE 000011DF 
2000FF90 = 000242D1 0000001F 00000001 80000000 
2000FFA0 = 50000000 00023727 00000021 00000039 
2000FFB0 = 0000001A 00000096 8485C80E 2E3BBCEA 
2000FFC0 = 12222139 12222139 00000FF8 00000002 
2000FFD0 = 00000005 00000009 20002E0C 00000000 
2000FFE0 = 00000000 20003B68 00000000 00000000 
2000FFF0 = 00000000 20000000 00000000 0001F4AB
Data RAM System Code RAM ICODE/DCODE
2000 F000 0080 F000
mem 20000000,800 0800 0000 
 
    80..FC customer   
mem 10001080,80 UICR

10000000 FICR:
    14..7C Nordic Firmware NRFFW[0..11] 
   8 0000 .. 80 ffff, code ram 
     0000 ..  7 FFFF, flash 

FICR->DEVICEID  not MAC
mem 10000060,8
10000060 = 1A 04 D7 6E 04 BA FA D1 


FICR->DEVICEADDRTYPE  FE public, FF random
mem 100000a0,4
FICR->DEVICEADDR
mem 100000a4,6       displayed as MAC 
1A 1E 4A 74 FA 37 ; F7:FA:74:4A:1E:1A 
03 AD 43 C6 C0 B2 ; F2:C0:C6:43:AD:03
0E 23 6C 9C 8B 14 ; D4:8B:9C:6C:23:0E
BC 20 DD 3F 38 A9 ; E9:38:3F:DD:20:BC
Load data file loadfile filename. bin | mot | hex | rec [,addr] for bin 
loadfile test_v3.28.13_full.hex
Downloading file [test_v3.28.13_full.hex]...
Comparing flash   [100%] Done.
Erasing flash     [100%] Done.
Programming flash [100%] Done.
Verifying flash   [100%] Done.
J-Link: Flash download: Bank 0 @ 0x00000000: 3 ranges affected (319488 bytes)   

J-Link: Flash download: Total time needed: 5.759s 
       (Prepare: 0.119s, Compare: 0.045s, Erase: 0.000s, Program: 5.492s, Verify: 0.015s, Restore: 0.086s)
O.K.

File is of unknown / supported format.
The file extension should be .hex or

Failed to open file.
File cannot be read or the file may have a checksum error or other format problem.

Erase flash . erase includes NRF_UICR->CUSTOMER 
Erasing device (nRF52832_xxAA)...
Comparing flash   [100%] Done.
Erasing flash     [100%] Done.
Verifying flash   [100%] Done.
J-Link: Flash download: Total time needed: 0.312s 
    (Prepare: 0.042s, Compare: 0.000s, Erase: 0.263s, Program: 0.000s, Verify: 0.000s, Restore: 0.006s)
Erasing done.


mem64 0,10
00000000 = FFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFF 
mem64 7FFE0,10
0007FFE0 = FFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFF 
0007FFF0 = FFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFF 
00080000 = 0000000000000000 0000000000000000 
00080010 = 0000000000000000 0000000000000000
Save memory

    layout

see nrfjprog --readuicr file.hex
--readcode , --readram

savebin filename, addr, NumBytes
in mem format i.e. 03 02 01 00 07 06 05 04
where mem32 shows 00010203 04050607 
savebin 1a96hungRAM.bin 20000000 65535

Opening binary file for writing... [1a96hungRAM.bin]
Reading 415029 bytes from addr 0x20000000 into file...O.K.
q

> hexdump -C 1a96hungRAM.bin > 1a96hungRAM.txt
> vi 1a96hungRAM.txt


savebin FICRUICR.bin 10001000 8192

Opening binary file for writing... [FICRUICR.bin]
Reading 33170 bytes from addr 0x10001000 into file...O.K.

hexdump -C FICRUICR.bin > FICRUICR.txt
vi FICRUICR.txt
savebin FDS.bin
Set Program Counter SetPC Addr
Single step s      Instruction displayed has already been executed!
WatchDog timer WILL expire during step and WDOG_HANDLER will be invoked after entering g 

J-Link>s
00024AFC:  4F F6 FF 72        MOVW      R2, #0xFFFF
J-Link>regs
PC = 00024B00, CycleCnt = 014A8587
R0 = 00000000, R1 = 00000000, R2 = 0000FFFF, R3 = 00000000 …

0001F832:  01 38              SUBS      R0, #1
J-Link>s
0001F834:  C3 D1              BNE       #-0x7A
J-Link>s
000008E4:  06 4B              LDR       R3, [PC, #+0x18]
…
0000031C:  4F F0 10 24        MOV       R4, #0x10001000     Config area
00000320:  A0 69              LDR       R0, [R4, #+0x18]
00000322:  40 1C              ADDS      R0, R0, #1
00000324:  05 D0              BEQ       #+0x0A
00000326:  A5 69              LDR       R5, [R4, #+0x18]
00000328:  A6 69              LDR       R6, [R4, #+0x18]
0000032A:  80 35              ADDS      R5, #128
0000032C:  30 79              LDRB      R0, [R6, #+0x04]
0000032E:  AA 28              CMP       R0, #170
00000330:  08 D0              BEQ       #+0x10
00000332:  60 69              LDR       R0, [R4, #+0x14]
00000334:  40 1C              ADDS      R0, R0, #1
00000336:  2D D0              BEQ       #+0x5A
00000338:  60 69              LDR       R0, [R4, #+0x14]
0000033A:  00 68              LDR       R0, [R0]
0000033C:  40 1C              ADDS      R0, R0, #1
0000033E:  29 D0              BEQ       #+0x52
00000340:  60 69              LDR       R0, [R4, #+0x14]
00000342:  2C E0              B         #+0x58

0000039E:  00 F0 A3 FA        BL        #+0x546

000008E8:  06 4A              LDR       R2, [PC, #+0x18]
000008EA:  10 60              STR       R0, [R2]
000008EC:  01 68              LDR       R1, [R0]
000008EE:  81 F3 08 88        MSR       MSP, R1
000008F2:  40 68              LDR       R0, [R0, #+0x04]
000008F4:  00 47              BX        R0



00009A9E:  20 BF              WFE  
00009AA0:  D4 F8 04 01        LDR       R0, [R4, #+0x104]
00009AA4:  00 28              CMP       R0, #0
00009AA6:  FA D0              BEQ       #-0x0C

00009A9E:  20 BF              WFE  
00009AA0:  D4 F8 04 01        LDR       R0, [R4, #+0x104]
00009AA4:  00 28              CMP       R0, #0

00079E18:  06 49              LDR       R1, [PC, #+0x18]
00079E1A:  07 4A              LDR       R2, [PC, #+0x1C]
instruction BreakPoint SetBP aaaaa [A|T] [S|H]
ARM mode: 2xxxx | Thumb mode: 0xAB Soft|hard

ClrBP handleID

Example:
Use grep to find startup.main from the LoaD map 

grep -A1 .text.startup.main   ruuvitag_b/s132/armgcc/_build/ruuvi_firmware.map 
 .text.startup.main
                0x0000000000024aec      0x518 _build/ruuvi_firmware_main.c.o
In j-link:
setBP 24aec 
Breakpoint set @ addr 0x00024AEC (Handle = 5)
When breakpoint is encountered a simple J-Link> prompt is presented.
Use moe to determine what happened.
     CPU halted due to code breakpoint match.
s executes next instruction.

Display breakpoints (i.e. FPB :(?) mem32 E0002000,10

ARM instructions

Reset r[x DelayAfterReset ]
sets ALL regs=0
>r
Reset delay: 0 ms
Reset type NORMAL: Resets core & peripherals via SYSRESETREQ & VECTRESET bit.
Reset: Halt core after reset via DEMCR.VC_CORERESET.
Reset: Reset device via AIRCR.SYSRESETREQ.
>s
000008E4:  06 4B              LDR       R3, [PC, #+0x18]     // first executable
000008E6:  18 47              BX        R3
Set the reset type. RSetType type Affects core & peripherals unless noted. See j-Link section 7.9.2 (Ruuvi / nRF52832 is Cortes-M4)
0Normal via VC_CORERESET and SYSRESETREQ.
  1. Make sure that the device halts immediately after reset
    (before it can execute any instruction of the user application) by setting the VC_CORERESET in the DEMCR .
  2. Reset the core and peripherals by setting the SYSRESETREQ bit in the AIRCR.
  3. Wait for the S_RESET_ST bit in the DHCSR to first become high(resetactive)and then low (reset no longer active) afterwards.
  4. ClearVC_CORERESET
1Core not recommended. Core only ( via VECTRESET bit, CPU does not start execution)
2ResetPin using RESET pin. CPU does not start execution.
3Connect under Reset connec to target keeping RESETactive.
4Halt After BTL as with 0 executes bootloader.(for LPC1xxx)
5Halt Before BTL as with 8 halts CPU before the bootloader.
6Kinetis via strategy NORMAL. Watchdog disabled after reset
7ADI Halt after kernel halts CPU after the ADI kernel.
8Core and Peripherals via SYSRESETREQ bit only.
9LPC1200 via strategy normal. Watchdog disabled after reset
10S3FN60D via strategy normal. Watchdog disabled after reset
11LPC11A Performs some special handling which is needed by some LPC11A bootloaders.
data WatchPoint SetWP|ClrWP Addr [R|W] [Data [D-Mask] [A-Mask]] 

SetWP 20002da2
Watchpoint set @ addr 0x20002DA2 (Handle = 0x00000004)
When breakpoint is encountered a simple J-Link> prompt is presented.
Use moe to determine what happened.
moe
     CPU halted due to data breakpoint unit 3 match
Load *.bin file loadbin filename.bin, addr
Verfy binary is in memory verifybin filename, addr
Wait until CPU halts or
timeout exceeded. 		WaitHalt TimeoutMs Default 1000
Wait Sleep ms
hardware status st 
VTref=3.300V
ITarget=0mA
TCK=0 TDI=1 TDO=1 TMS=1 TRES=1 TRST=1
Supported target interface speeds:
- 10 MHz/n, (n=10). = 1000kHz, 909kHz, 833kHz, ...
hardware info hwinfo / 
HWInfo[00] = Target power is disabled
HWInfo[02] = 0mA	(ITarget)
HWInfo[03] = 0mA	(ITargetPeak)
HWInfo[04] = 0mA	(ITargetPeakOperation)
HWInfo[10] = 0ms	(ITargetMaxTime0)
HWInfo[11] = 0ms	(ITargetMaxTime1)
HWInfo[12] = 0ms	(ITargetMaxTime2)
HWInfo[13] = 0000000
Write vector catch. VCatch Value
Unlock a device. unlock DeviceName

list of supported device names. 

LM3Sxxx [Auto]
Kinetis
EFM32Gxxx
LPC5460x 
           nRESET has to be connected
Test command to visualize printf output from the target device, term using DCC (SEGGER DCC handler running on target)
CoreSight register ReadAP
ReadDP 
 J-Link>readap 2
Reading AP register 1 = 0x20002007 (0 read repetitions needed)
J-Link>readap 2
Reading AP register 2 = 0x00000000 (0 read repetitions needed)
J-Link>readap 3
Reading AP register 3 = 0xA044E7D5 (0 read repetitions needed)
J-Link>readap 4
Reading AP register 4 = 0x23000052 (0 read repetitions needed)
J-Link>readap 5
Reading AP register 5 = 0x20006000 (0 read repetitions needed)
J-Link>readap 6
Reading AP register 6 = 0x00000000 (0 read repetitions needed)
J-Link>readap 7
Reading AP register 7 = 0xF203BEDA (0 read repetitions needed)
J-Link>readap 8
Reading AP register 8 = 0x23000052 (0 read repetitions needed)
J-Link>readap 9
Reading AP register 9 = 0x20003000 (0 read repetitions needed)

J-Link>readap 1
Reading AP register 1 = 0x20002000 (0 read repetitions needed)
J-Link>readap 1
Reading AP register 1 = 0x20004000 (0 read repetitions needed)
J-Link>readap 1
Reading AP register 1 = 0x20002000 (0 read repetitions needed)
J-Link>readap 1
Reading AP register 1 = 0x20000000 (0 read repetitions needed)
J-Link>readap 1
Reading AP register 1 = 0x20006000 (0 read repetitions needed)
J-Link>readap 1
Reading AP register 1 = 0x20004000 (0 read repetitions needed)
J-Link>readap 1
Reading AP register 1 = 0x20002007 (0 read repetitions needed)
J-Link>readap 1
Reading AP register 1 = 0x20005000 (0 read repetitions needed)

First read returns the data of the previous read. An additional read of DP reg 3 is necessary to get the data.
For SWD, data is returned immediately.
For JTAG the data of the previous read is returned. An additional read of DP reg 3 is necessary to get the data.

WriteAP
WriteDP

CoreSight register via SWD. SWDReadDP 
J-Link>SWDReadDP 1
Read DP register 1 = 0xF0000040
J-Link>SWDReadDP 2
Read DP register 2 = 0xE000ED34
Read DP register 3 = 0xE000ED34
Read DP register 4 = 0xE000ED34
Read DP register 5 = 0x23000052
Read DP register 6 = 0xE000ED34
SWDReadAPM
First read returns the data of the previous read.
An additional read of DP reg 3 is necessary to get the data. Note: Correct data is returned immediately.
SWDWriteAP
SWDWriteDP
Export device names from the DLL internal device list ExpDevList[XML] Filename 
Opening text file for writing... [DLL-list]
DLLs 
…

"Nordic Semi", "nRF52832_xxAA", "Cortex-M4", { {0x00000000, 0x00080000}, {0x10001000, 0x00001000} }, {0x20000000, 0x00010000}
"Nordic Semi", "nRF52832_xxAB", "Cortex-M4", { {0x00000000, 0x00040000}, {0x10001000, 0x00001000} }, {0x20000000, 0x00008000}
"Nordic Semi", "nRF52840_xxAA", "Cortex-M4", { {0x00000000, 0x00100000}, {0x10001000, 0x00001000} }, {0x20000000, 0x00040000}
"Nordic Semi", "nRF9160", "Cortex-M33", {0x00000000, 0x00100000}, {0x20000000, 0x00040000}
power trace PowerTrace LogFile 
        [ChannelMask RefCountSel]
        LogFile: File to store power trace data to
        ChannelMask: 32-bit mask to specify what channels shall be enabled
        SampleFreq: Sampling frequency in Hz (0 == max)
        RefCountSel:       0: No reference count
1: Number of bytes transmitted on SWO
ERROR: POWERTRACE is not supported by connected J-Link.
Measure length of scan chain. ms Scan chain
Identify length of scan chain select register is
Measure RTCK react time. mr
Write test words. wm NumWords
CP15
Read |Write CP15 rce | wce Op1, CRn, CRm, Op2 [, data
ICE
state of the embedded ice macrocell (ICE breaker) Ice
Read | write Ice reg. ri | wi RegIndex [, Data(hex)]
Trace
TClear
TStart | TStop
TSetSize
TSetFormat
Regions (and analyze trace buffer) TSR
Periodic
PERConf
PERStart | PERStop
PERStat
PERRead
Read and analyze data PERShow
File I/O
Read|Write file to emulator fread|fwrite
Read and display file from emulator fshow FileName [Offset [NumBytes]]
Delete file on emulator fdelete FileName
Display size of file on emulator fsize FileName
List directory on emulator flist 
This File I/O command is not supported by the connected probe
SecureArea Creates/Removes secure area on probe
Test
Run go/halt 1000 timesTestHaltGo
  ................................
Completed. 8420ms required
Run step 1000 timesTestStep
Measure CPU speed. TestCSpeed [RAMAddr]
Measure download speed into target memory. TestWSpeed [Addr [Size]]
Measure upload speed from target memory. TestRSpeed : [Addr [Size] [NumBlocks]]
Measure network speed: download(write)/up(read) TestNWSpeed: [NumBytes [NumReps]]
TestNDWSpeed: [NumBytes [NumReps]]
JTAG
Set number of IR/DR bits before ARM device. Config IRpre, DRpre
Set interface speed. speed freq|auto|adaptive, e.g. speed 2000, speed a
Read JTAG Id (Host CPU)
Write JTAG command (IR). wjc xData
Write JTAG data (DR). wjd xData64, NumBits(dec)
Write Raw JTAG data. wjraw NumBits(dec), tms, tdi
RTAP Reset TAP Controller using state machine (111110)
Reset TA0P Controller (nTRST) rt
JTAG-Hardware
Create clock with
TDI = TMS = 0m 		c00
c Clock ====== see 16.1.1
Clear | set TCK tck0 | 1 test clock input (TCK) provides the clock for the test logic.
Clear | set TDI 0 | 1 Serial test instructions and data are received by the test logic at test data input
Clear | set TMS t0 | 1 signal received at test mode select (TMS) is decoded by the TAP controller to control test operations.
Clear | set TRS Ttrst0 | 1 Test data output (TDO) is the serial output for test instructions and data from the test logic.
Clear | set RESET r0 |1 (sic?
Connection
Connect ARM Pro or J-Link TCP/IP Server via TCP/IP. ip ip_addr
 
Connecting to J-Link via IP...
FAILED: Can not connect to J-Link via TCP/IP (192.168.1.1, port 19020)
Show/Assign IP address and subnetmask of/to the connected J-Link. ipaddr 
Disconnecting from J-Link...O.K.
Disconnecting from J-Link...O.K.
Connecting to J-Link via IP...FAILED: Can not connect to J-Link via TCP/IP. No emulator found.
Show/Assign network gateway . gwaddr
Show/Assign network DNS server . dnsaddr
Configuration
Switch power supply for target. power on|off [perm]
The connected debug probe does not support this command.
Read/Write configuration byte rconf|wconf offset [, data] 
rconf 0,80
Total size of config area: 0x100 bytes

00000000 = 00 01 FF FF FF FF FF FF FF FF FF FF FF FF FF FF 
00000010 = FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 
00000020 = FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 
00000030 = FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 
00000040 = FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 
00000050 = 00 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 
00000060 = FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 
00000070 = FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
Configuration of the connected J-Link. [show]conf
USB-Address: 0
Enum. type:  Real-SN is used
KS-Power:    Off (Default)
SWO SoftWare Output
supported speeds SWOSpeed 
Supported speeds:
 - 12000 kHz/n, (n>=1). => 12000kHz, 6000kHz, 4000kHz, ...
SWOStart| SWOStop
Display SWO status SWOStat after logging but not displayed vi RTviewerclient1, 
MAIN:INFO:LEDs init
 J-Link>SWOStat
0 bytes in host buffer
However SWOread showed data and SWOstat
Read and display SWO data SWORead 

SWOStat
0 bytes in host buffer
J-Link>SWORead
256 bytes read (0 bytes in host buffer)
00000000 = 00 00 00 00 00 00 00 90 00 00 00 00 00 00 00 90 
00000010 = 37 00 00 00 A3 59 00 8B 70 A0 16 0C 01 00 00 00 
00000020 = 50 62 59 54 FF 7F 00 00 02 00 00 00 00 00 07 00 
00000030 = 00 00 00 00 00 00 00 90 00 00 00 00 00 00 00 90 
00000040 = 4F 00 00 00 00 00 00 00 10 00 10 00 10 00 00 00 
00000050 = 00 00 00 00 00 00 00 00 00 00 00 2C 06 00 16 00 16 00 21 see SWOshow PC
00000060 = 21 00 00 00 40 00 00 00 41 00 00 00 42 00 00 00 
00000070 = 43 00 00 00 44 00 00 00 45 00 00 00 46 00 00 00 
…
000000F0 = 4F 00 00 00 50 00 00 00 51 00 00 00 52 00 00 00
Read and analyze SWO data SWOShow 
J-Link>SWOShow
256 bytes read (0 bytes in host buffer)
Offset     Data               Meaning
-----------------------------------------------
001E-0020  16 00 21           PC = 0x00002100
0024-0024  40                 Timestamp sync. ITM/DWT (4)
0028-0029  41 00              SWIT(8): 00
002C-002E  42 00 16           SWIT(8): 00 16
0034-0035  01 00              SWIT(0): 00
0038-003A  02 00 00           SWIT(0): 00 00
003C-0040  03 00 00 00 04     SWIT(0): 00 00 00 04
0044-0045  05 00              Event counter ()
0048-....  06                 Unknown packet
Flush data SWOFlush
View terminal data SWOView 
 Receiving SWO data @ 6000 kHz.
Data from stimulus port 0:
-----------------------------------------------
Calibrate the target current measurement.calibrate
Please disconnect emulator from target.
Press any key to start the calibration...

Calibrating...Emulator calibrated.
Min=-1mA Max=-1mA Avg=-1mA Offs=-1mA...DONE
Change endian mode le be little | big
Select a emulator to communicate selemu [Interface0 Interface1 ...]
list all emulators which are connected to the host. ShowEmuList [Interface0 Interface1 ...]
J-Link[0]: Connection: USB, Serial number: 682930364, ProductName: J-Link OB-SAM3U128-V2-NordicSem
Set value for VTref VTREF ValuemV
15.4 Reference voltage (VTref)
VTref is the target reference voltage. used by the J-Link to check if the target has power, to create the logic-level reference for the input comparators and to control the output logic levels to the target. It is normally fed from Vdd of the target board and must not have a series resistor.
In cases where the VTref signal should not be wired to save one more pin / place on the target hardware interface connector (e.g. in production environments), SEGGER offers a special adapter called J-Link Supply Adapter which can be used for such purposes. Further information regarding this, can be found on the SEGGER website ( J-Link supply adapter )
To guarantee proper debug functionality, connect at least on of the GND pins to GND (Pin 4, 6, 8, 10, 12, 14*, 16*, 18*, 20*).
On some models like the J-Link ULTRA, these pins are reserved for firmware extension purposes. They can be left open or connected to GND in normal debug environ- ment. Please do not assume them to be connected to GND inside J-Link.
log actionslog filename (reformated somewhat) Shell commands to monitor log :
> taill -f |sed "s/FPS[12][0-9]=0x00,//g; s/FPS[1-9]=0x00,//g"

taill -f |sed "s/FPS[12][0-9]=0x00,//g; s/FPS[1-9]=0x00,//g; s/0x//g; s/JLINK_//; s/0000ms,//g; s/ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 17, 18, 14, 15, 16,/0..18/; s/33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,/33..63/" 

 tail jl180603 


T9C4E9380 2450:057 Step() -- Read from C cache (2 bytes @ 1F81E) 
                    -- Simulated            returns 0 (0ms, 777ms total)
T9C4E9380 2450:269 IsHalted()         returns TRUE 
T9C4E9380 2450:269 GetDeviceFamily()  returns 14 
T9C4E9380 2450:269 ReadReg(R15 (PC))  returns 1F820 
T9C4E9380 2450:269 DisassembleInst(Addr = 1F820)

                ReadMemEx(01F820, 2 Bytes, ..., Flags = 0) 
                    -- Read from C cache (2 bytes @ 1F820) - Data: 0 BF  returns 2 (0ms, 0ms total)
                                            returns 2 
T9C4E9380 2450:269 GetDeviceFamily()  returns 14 
T9C4E9380 2450:269 ReadMemEx(1F820, 2 Bytes, ..., Flags = 0) 
                    -- Read from C cache (2 bytes @ 1F820) - Data: 0 BF  returns 2 
T9C4E9380 2450:269 Step() 
                    -- Read from C cache (2 bytes @ 1F820) -- Simulated  returns 0 (0ms, 777ms total)
//Read from C cache

halt LOG:

T9C4E9380 4257:596 JLINK_Halt()  returns 0 (0007ms, 0438ms total)
T9C4E9380 4257:603 JLINK_GetDeviceFamily()  returns 14 ( 0438ms total)
T9C4E9380 4257:603 JLINK_CORE_GetFound()  returns 0xE0000FF ( 0438ms total)
T9C4E9380 4257:603 JLINK_GetDeviceFamily()  returns 14 ( 0438ms total)
T9C4E9380 4257:603 JLINK_CORE_GetFound()  returns 0xE0000FF ( 0438ms total)
T9C4E9380 4257:603 JLINK_GetDebugInfo(0x01 = Unknown) 
                            -- Value=0000001  returns 0 ( 0438ms total)
T9C4E9380 4257:603 JLINK_GetDebugInfo(0x10F = JLINKARM_DEBUG_INFO_HAS_CORTEX_M_SECURITY_EXT_INDEX) 
                            -- Value=0000000  returns 0 ( 0438ms total)
T9C4E9380 4257:603 JLINK_ReadRegs(NumRegs = 28, 
    Indexes: 0.. 13, 17, 18, 14, 15, 16, 21, 22, 23, 20, 27, 26, 25, 24, 65)   not 19, notice order, see below
                            -- CPU_ReadMem(4 bytes @ 0xE0001004)
 -- R0=5027E, R1=7A120, R2=F42400, R3=50000000, R4=F42400, R5=3D09000, R6=80000, R7=20000, R8=0, 
    R9=0, R10=20000000, R11=0, R12=20007DF8, 
    R13 (SP)=2000FFF8, MSP=2000FFF8, PSP=0, R14=1F6A1, R15 (PC)=1F776,
    XPSR=21000000, APSR=20000000, EPSR=1000000, IPSR=0, CFBP=0, CONTROL=0, FAULTMASK=0, BASEPRI=0, PRIMASK=0,
     CycleCnt=9B714FAC  returns 0 (1ms, 439ms total)
T9C4E9380 4257:604 JLINK_ReadRegs(NumRegs = 33, 
    Indexes: 33, …, 64, 32)
 -- FPS0=0, …,  FPS31=0, FPSCR=0  returns 0 (10ms,449ms total)
g log:
T9C4E9380 4819:214 JLINK_GoEx(MaxEmulInsts = 0, Flags = 01) -- CPU_ReadMem(4 bytes @ E0001000) (3ms, 452ms total)
+=
list license commandslicense 
license add   Store a custom license on J-Link. Syntax: LicAdd LicName
  license erase Erase all custom licenses on J-Link.
  license show  Show all licenses stored on J-Link.
J-Link>license show
Built-in licenses: 
No installable licenses.
Firmware info f 
Firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Jan 12 2018 16:05:20
Hardware: V1.00
Select device Device
Allows use of the J-Link flash programming as well as using unlimited breakpoints in flash memory.
mandatory For some devices to allow the DLL to perform special handling.
Select target interface. si SWD | JTAG | ICSP | FINE | …
Select SWD as interface and outputs the JTAG - SWD switching sequence. SWDSelect
current CPU state IsHalted 
        CPU is not halted.
Close connection and quitqc

Wish it had

Memory search,
logger

NRF_LOG_LEVEL
NRF_LOG_DEFAULT_LEVEL
NRF_LOG_[HEXDUMP_] ERROR | WARNING | INFO | RAW_INFO | DEBUG

printf-like, formatted string with up to seven arguments.

With HEXDUMP arg.2 is length.

Compiled only if NRF_LOG_LEVEL includes xxx
GETCHGAR (waits),
FLOAT[_MARKER]

NRF_LOG_LEVEL

Add -M to LDFLAGS +=… to generate symbol map.

OverTheAir D FirmwareUpload
075B20 

-> /Applications/SEGGER/JLink_V633a/JFlashLite.app
JFlashLite.app                      JFlashLite          
JFlashSPI          
JLinkExe          
JLinkGDBServer.app                  JLinkGDBServer   
JLinkGDBServerCL  
JLinkLicenseManager.app 
JLinkRegistration.app 
JLinkRemoteServer.app               JLinkRemoteServer   
JLinkRemoteServerCLExe 
JLinkRTTClient      
JLinkRTTLogger      
JLinkSTM32         
JLinkSWOViewer    
JTAGLoadExe      
nrfjprog            -> /usr/local/Caskroom/nordic-nrf5x-command-line-tools/53406.17.93573317/nrfjprog/nrfjprog
mergehex            -> /usr/local/Caskroom/nordic-nrf5x-command-line-tools/53406.17.93573317/mergehex/mergehex
gcc-arm-none-eabi-4_9-2015q3-20150921-mac.tar
gcc-arm-none-eabi-4_9-2015q3/

Sample startup


4/28/19 JLink_MacOSX_V645d.pkg (finder  control click to open)


/Applications/SEGGER/JLink/JLinkExe #      s swd ; Speed
SEGGER J-Link Commander V6.45d (Compiled Apr  5 2019 17:04:01)
DLL version V6.45d, compiled Apr  5 2019 17:03:50

Connecting to J-Link via USB...O.K.
Firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Jan  7 2019 14:07:15
Hardware version: V1.00
S/N: 682394615
VTref=3.300V


Type "connect" to establish a target connection, '?' for help
J-Link>connect
Please specify device / core. : NRF52832_XXAA
Type '?' for selection dialog
Device>
Please specify target interface:
  J) JTAG (Default)
  S) SWD
  T) cJTAG
TIF>s
Specify target interface speed [kHz]. : 4000 kHz
Speed>
Device "NRF52832_XXAA" selected.


Connecting to target via SWD
Found SW-DP with ID 0x2BA01477
Found SW-DP with ID 0x2BA01477
Scanning AP map to find all available APs
AP[2]: Stopped AP scan as end of AP map has been reached
AP[0]: AHB-AP (IDR: 0x24770011)
AP[1]: JTAG-AP (IDR: 0x02880000)
Iterating through AP map to find AHB-AP to use
AP[0]: Core found
AP[0]: AHB-AP ROM base: 0xE00FF000
CPUID register: 0x410FC241. Implementer code: 0x41 (ARM)
Found Cortex-M4 r0p1, Little endian.
FPUnit: 6 code (BP) slots and 2 literal slots
CoreSight components:
ROMTbl[0] @ E00FF000
ROMTbl[0][0]: E000E000, CID: B105E00D, PID: 000BB00C SCS-M7
ROMTbl[0][1]: E0001000, CID: B105E00D, PID: 003BB002 DWT
ROMTbl[0][2]: E0002000, CID: B105E00D, PID: 002BB003 FPB
ROMTbl[0][3]: E0000000, CID: B105E00D, PID: 003BB001 ITM
ROMTbl[0][4]: E0040000, CID: B105900D, PID: 000BB9A1 TPIU
ROMTbl[0][5]: E0041000, CID: B105900D, PID: 000BB925 ETM
Cortex-M4 identified.

Errors

Connecting to J-Link via USB...FAILED: Cannot connect to J-Link via USB.

Is Nordic Dev board switched on?

Try another cable in case the USB is not a "power-only" (i.e. no-data) cable.

File is of unknown / supported format.
The file extension should be .hex or

Failed to open file.
The file may have a checksum err or or other format problem.

The connected J-Link (S/N xxxxxxxxx) is low on memory

WDOG notes

Segger download page

UM08001_JLink.pdf

Intel HEX format

Nordic Semiconductor nrfjprog Command Line interface to J-Link.

Not to be confused with /usr/bin/jlink which is part of the Sun (now oracale) java system!