NRF52840 Development

Open three terminals in the /opt/SEGGER/JLink_V622g directory.

1. start remote server

$ ./JLinkRemoteServer
UseTunnel

SEGGER J-Link Remote Server V6.22g
Compiled Jan 17 2018 16:40:43 

'q' to quit '?' for help

Connected to J-Link with S/N 683525645

Waiting for client connection... 

2. start RTT client

$ ./JLinkRTTClient

###RTT Client: ************************************************************ 
###RTT Client: *           SEGGER MICROCONTROLLER GmbH & Co KG            * 
###RTT Client: *   Solutions for real time microcontroller applications   * 
###RTT Client: ************************************************************ 
###RTT Client: *                                                          * 
###RTT Client: *  (c) 2012 - 2016  SEGGER Microcontroller GmbH & Co KG    * 
###RTT Client: *                                                          * 
###RTT Client: *     www.segger.com     Support: support@segger.com       * 
###RTT Client: *                                                          * 
###RTT Client: ************************************************************ 
###RTT Client: *                                                          * 
###RTT Client: * SEGGER J-Link RTT Client   Compiled Jan 17 2018 16:40:49 * 
###RTT Client: *                                                          * 
###RTT Client: ************************************************************ 

###RTT Client: -----------------------------------------------
###RTT Client: Connecting to J-Link RTT Server via localhost:19021  Connected.
###RTT Client: Connection lost. Going to reconnect.
###RTT Client: Connecting to J-Link RTT Server via localhost:19021 .............. Connected.
SEGGER J-Link V6.22g - Real time terminal output
J-Link OB-SAM3U128-V2-NordicSemi compiled Jan 12 2018 16:05:20 V1.0, SN=683525645
Process: JLinkRemoteServer

SPI Initialized.
reset_AD7124.
Reset failed:  0x00

3. start JLinkExe

connect
NRF52840_XXAA
S
<Enter>

$ ./JLinkExe
SEGGER J-Link Commander V6.22g (Compiled Jan 17 2018 16:40:37)
DLL version V6.22g, compiled Jan 17 2018 16:40:32  

Connecting to J-Link via USB...O.K.
Firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Jan 12 2018 16:05:20
Hardware version: V1.00
S/N: 683525645
VTref = 3.300V


Type "connect" to establish a target connection, '?' for help
J-Link>connect
Please specify device / core. <Default>: NRF52832_XXAA
Type '?' for selection dialog
Device>NRF52840_XXAA
Please specify target interface:
 J) JTAG (Default)
 S) SWD
TIF>S
Specify target interface speed [kHz]. <Default>: 4000 kHz
Speed>
Device "NRF52840_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.
J-Link>

To compile, flash and reset:

~/Projects/nRF5_SDK_14.2.0_17b948a/examples/peripheral/spi/pca10056/blank/armgcc

$ make
$ nrfjprog -f NRF52 --program _build/nrf52840_xxaa.hex --sectorerase
$ nrfjprog -f NRF52 --reset