J-Link / J-Trace
User Guide
Document: UM08001
Software Version: 7.68
Date: July 14, 2022
A product of SEGGER Microcontroller GmbH
www.segger.com
2
Disclaimer
The information written in this document is assumed to be accurate without guarantee. The
information in this manual is subject to change for functional or performance improvements
without notice. SEGGER Microcontroller GmbH (SEGGER) assumes no responsibility for any errors
or omissions in this document. SEGGER disclaims any warranties or conditions, express, implied
or statutory for the fitness of the product for a particular purpose. It is your sole responsibility
to evaluate the fitness of the product for any specific use.
Copyright notice
You may not extract portions of this manual or modify the PDF file in any way without the prior
written permission of SEGGER. The software described in this document is furnished under a
license and may only be used or copied in accordance with the terms of such a license.
© 2004-2021 SEGGER Microcontroller GmbH, Monheim am Rhein / Germany
Trademarks
Names mentioned in this manual may be trademarks of their respective companies.
Brand and product names are trademarks or registered trademarks of their respective holders.
Contact address
SEGGER Microcontroller GmbH
Ecolab-Allee 5
D-40789 Monheim am Rhein
Germany
Tel.
Fax.
E-mail:
Internet:
+49-2173-99312-0
+49-2173-99312-28
support@segger.com
www.segger.com
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
3
Manual versions
This manual describes the current software version. If you find an error in the manual or a
problem in the software, please report it to us and we will try to assist you as soon as possible.
Contact us for further information on topics or functions that are not yet documented.
Print date: July 14, 2022
Manual
Revision
version
7.65e
0
Date
By
Description
220509
LG
Chapter “Target interfaces and adapters”
* Section “20-pin J-Link connector”: Added sub-section “Pinout for QSPI”
7.62
0
220212
MK
Chapter “Open Flashloader”
* Section “General procedure”: Updated information regarding usage of
JLinkDevices folder.
* Section “Information for Silicon Vendors”: Updated information regarding
usage of JLinkDevices folder.
DisableLTRACEAnalysis
7.52
0
210730
NV
Chapter “Working with J-Link and J-Trace”
* Section “J-link Command Strings”: Added
DisableLTRACEAnalysis
7.50
0
210707
EL
Chapter “Reset strategies”
*Moved section to the wiki
7.00a
0
210419
LG
Chapter “Target interfaces and adapters”
*Section “20-pin J-Link connector”
*Section “Pinout for SWD”
*Section “Target power supply”:
The word “perm” was part of the wrong column. Fixed.
7.00a
0
210419
LG
Chapter “Target interfaces and adapters”
*Section “Reference voltage (VTref)”:
Typo: “on” instead of “one. Fixed.
7.00a
0
210419
LG
Chapter ”Target interfaces and adapters“
*Section ”Reference voltage (VTref)“:
Added link to wiki article for setting a fixed VTref via J-Link Commander.
SI
Chapter ”Working with J-Link and J-Trace“
*Section ”JTAG interface“
*Section ”Multiple devices in the scan chain“:
Number of supported JTAG-chain devices updated to 32. Fixed.
6.98e
0
210401
6.94
0
210224
FF
Chapter ”Working with J-Link and J-Trace“
*Section ”J-Link script files“
*Section ”Supported Operators“:
Modulo operator was listed as supported even though it is not. Fixed.
6.88
0
201113
NV
Chapter ”Working with J-Link and J-Trace“
*Section ”J-Link Command Strings“ added command string TraceFile.
6.88
0
201113
FF
Chapter ”RTT“
*Section ”API functions“:
SEGGER_RTT_ConfigDownBuffer and SEGGER_RTT_ConfigUpBuffer: In the
”Example“ section both functions were falsely named. Fixed.
6.86
0
201015
DL
Chapter ”J-Link Command Strings“
Added missing parameters of command ”SetCFIFlash“
6.80
0
200324
FF
Chapter ”JTAGLoad“
Added missing command line option ”-LogFile“
LG
Chapter ”J-Link GDB Server“
*Section ”Command line options“:
Replaced occurrences of ”OS X“ with ”macOS“.
Chapter ”J-Flash SPI“
Updated for recently added cross-platform availability of J-Flash SPI.
6.64
0
200324
6.64
0
200317
LG
Chapter ”J-Link Commander (Command line tool)“
*Section ”Command line options“:
Moved to SEGGER wiki.
*Section ”Using J-Link Command Files“:
Moved to SEGGER wiki.
6.60
0
200106
LG
Chapter ”J-Link Commander (Command line tool)“
*Section ”Commands“:
Moved to SEGGER wiki.
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
4
Manual
Revision
version
Date
By
Description
6.56
0
191127
NV
Chapter ”Working with J-Link and J-Trace“
*Section ”J-Link Command Strings“:
Expanded coresight baseaddr commands.
6.54
4
191121
NV
Chapter ”RTT“
*Section ”Implementation“:
Added API function SEGGER_RTT_GetAvailWriteSpace().
6.54
3
191120
DL
Chapter ”J-Link GDB Server“
*Section ”Command line options“:
Added information for command line option ”-rtos“ where to request the
SDK for creating plug-ins.
6.54
2
191120
DL
Chapter ”J-Link software and documentation package“
*Section ”J-Link Commander (Command line tool)“:
Added note for VTREF command.
6.54
1
191105
FF
Chapter ”Working with J-Link and J-Trace“
*Section ”J-Link script files“:
Added default return value information for J-Link script file functions.
6.54
0
191023
AG
Chapter ”Working with J-Link and J-Trace“
*Section ”J-Link WiFi setup“ added
6.52
0
191021
AG
Chapter ”Semihosting“
*Section ”Debugger Support“
Took off Keil MDK-ARM of the list of supported IDEs as MDK does not support semihosting.
6.52
0
191016
LG
Chapter ”RTT“
*Section ”Example code“ updated.
LG
Chapter ”J-Link software and documentation package“
*Section ”J-Link Remote Server“
Added command ”-TunnelEncrypt“
Added subsection ”Encrypted connection“
6.50
0
191016
6.50
0
190923
DL
Chapter ”J-Link software and documentation package“
*Section ”J-Link Remote Server“: Updated screenshots
*Section ”J-Link Remote Server“: Created examples for the syntax of the
connect-string
6.48
2
190813
AG
Chapter ”J-Link software and documentation package“
* Section ”J-Link GDB Server“: Command line option ”-JLinkDevicesXMLPath“ corrected.
6.48
1
190802
DL
Chapter ”J-Link software and documentation package“
* Section ”J-Link Commander (Command line tool)
Added command “SetTimeoutCmd”
Added command “readcsr”
Added command “stepover”
Added command “writecsr”
6.48
0
190711
LG
Chapter “J-Link software and documentation package”
* Section “J-Link Commander (Command line tool)
Added command ”WebUSBEnable“
Added command ”WebUSBDisable“
6.46
0
190511
LG
Chapter ”J-Link software and documentation package“
* Section ”J-Link RTT Viewer“: Updated screenshots.
* Section ”J-Link RTT Viewer“: Menu entry ’Channel infos…’.
* Section ”J-Link Remote Server“: Updated list of available command line
options.
6.44
4
190424
AG
Chapter ”Target interfaces and adapters“
* Section ”20-pin J-Link connector“: Corrected information for pins 14, 16,
18, 20.
6.44
3
190415
LG
Chapter ”J-Link software and documentation pacakge“
* Updated J-Mem screenshot.
Added Chapter ”J-Mem“
6.44
2
190408
NV
Chapter ”Target interfaces and adapters“
* Added diagram showing J-Trace PRO connection with target device.
6.44
1
190321
EL
Chapter ”J-Link software and documentation package“
* Section ”J-Link GDB Server“: Command line options corrected.
6.44
0
190306
NV
Chapter ”J-Link software and documentation package“
* Section ”J-Link Commander“: Added memory zone example for command ”mem“.
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
5
Manual
Revision
version
Date
By
Description
6.42
0
190215
NV
Chapter ”Working with J-Link and J-Trace“
* Section ”J-Link Script Files“: Added new Scripting functions for ETB initialization.
Chapter ”Working with J-Link and J-Trace“
* Section ”J-Link Command Strings“: Expanded ”map region“ documentation.
6.40
1
181217
SI
Chapter ”J-Link software and documentation package“
* Section ” J-Link SWO Viewer: Added description of command line option
“-usb”“.
6.40
0
181120
AG
Chapter ”ARM SWD specifics“ added
Chapter ”ARM SWD specifics“
* Section ”SWD multi-drop“ added
6.34
10
181025
NV
Chapter ”J-Link software and documentation package“
* Section ”J-Link SWO Viewer“: Updated description and pictures.
6.34
9
181023
NV
Chapter ”Working with J-Link and J-Trace“
* Section ”J-Link Command Strings“: Added new J-Link command string
”RTTTelnetAllowNonLocalClient“.
6.34
8
101018
AG
Chapter ”Target interfaces and adapters“
* Section ”19-pin JTAG/SWD and Trace connector“: Added information
about pitch of connector.
6.34
7
180906
SI
Chapter ”J-Link Commander“
* Section ” Commands: Added description of “VTREF”.
6.34
6
180905
NV
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Script files”: Added new Script file functions to replace
generic trace module initializations.
6.34
5
180816
LG
Chapter “J-Link GDB Server”
* Section “Supported remote (monitor) commands”: Added new monitor
command “flash erase”.
6.34
4
180704
AG
Chapter “J-Link software and documentation package”
* Section “J-Flash Lite” added.
6.34
3
180524
LG
Chapter “J-Link software and documentation package”
* Section “J-Link Commander (Command line tool)”: Added new command
line option “-Log”.
6.34
2
180517
LG
Chapter “Open Flashloader”
* Section “XML Tags and Attributes”: Added new attribute
“Aliases”.
6.34
1
180516
NV
Chapter “J-Link software and documentation package”
* Section “J-Link SWO Viewer”: Refined CL option descriptions.
AG
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Command Strings”: Added new J-Link command string
“SetEnableMemCache”.
Chapter “Environmental Conditions & Safety” added
6.34
0
180511
6.32
4
180417
NV
Chapter “J-Flash SPI”
* Section “Command Line Interface”: Updated description of CL option jflashlog.
* Section “Command Line Interface”: Updated description of CL option jlinklog.
6.32
3
180409
NV
Chapter “Working with J-Link and J-Trace”
* Section “Script file API functions”: Added new API functions
“JLINK_MEM_Preserve()”, “JLINK_MEM_Restore()”, “JLINK_MEM_Fill()”.
6.32
2
180327
LG
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Command Strings”: Added new J-Link command string
“MemPreserveOnReset”.
6.32
1
180327
AG
Moved contents of chapter “Segger-specific GDB protocol extensions” to
separate manual (UM08036)
6.32
0
180323
AG
Moved J-Link GDB Server to separate chapter
Added Segger specific GDB protocol extension qSeggerSTRACE:caps
Added Segger specific GDB protocol extension qSeggerSTRACE:GetInstStats
6.30
2
180314
AG
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Command Strings”: Added new J-Link command string
“SetAllowStopMode”.
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
6
Manual
Revision
version
6.30
1
Date
180309
By
Description
NV
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Script Files”:
Added new function SWO_EnableTarget();.
* Section “J-Link Script Files”:
Renamed function GetSWOBaseClock() to SWO_GetSWOBaseClock();
Added unit information of clock speed value.
6.30
0
180206
EL
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Script Files”:
Added new function: HandleBeforeFlashProg();
* Section “J-Link Script Files”:
Added new function HandleAfterFlashProg();
6.24
1
180124
EL
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Comamnd Strings”: Updated.
6.24
0
180111
LG
Chapter “J-Link software and documentation package”
* Section “J-Link GDB Server”: Added new GDBServer monitor commands:
ReadAP, ReadDP, WriteAP and WriteDP.
NV
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Command Strings”: Added new J-Link Command String
to set base addresses of coresight components for tracing
e.g. CORESIGHT_SetETBBaseAddr.
* Section “J-Link script files”: Added new function GetSWOBaseClock();.
Chapter “J-Link software and documentation package”
* Section “J-Link SWO Viewer”: Updated picture of new SWO Viewer GUI
interface with additional explanation of SWO clock setting.
6.22
0
171214
6.20
8
171123
AG
Chapter “Related Software”
* Section “JTAGLoad”: PIO commands was listed as supported even though
it is not. Fixed.
* Section “JTAGLoad”: PIOMAP commands was listed as supported even
though it is not. Fixed.
6.20
7
171025
EL
Chapter “Monitor Mode Debugging”
* Section “Enable Monitor Debugging”: Updated
6.20
6
171013
EL
Chapter “Working with J-Link and J-Trace”
* Section “J-Link script files”: Updated
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Command Strings”: Updated
6.20
5
171011
NG
Updated links to SEGGER wiki:
Low power mode debugging
J-Link script files
J-Link Command Strings
6.20
4
171011
NG
Chapter “Working with J-Link and J-Trace”
* Section “Script file API functions”: Added the following functions:
JLINK_C2_WriteData()
JLINK_C2_ReadData()
JLINK_C2_WriteAddr()
JLINK_C2_ReadAddr()
JLINK_CORESIGHT_ReadDAP()
JLINK_GetPinState()
JLINK_GetTime()
JLINK_JTAG_ReadWriteBits()
JLINK_JTAG_StartDR()
JLINK_PIN_Override()
JLINK_SelectTIF()
JLINK_SetDevice()
JLINK_SWD_ReadWriteBits()
JLINK_TARGET_IsHalted()
JLINK_TARGET_Halt()
JLINK_TIF_ActivateTargetReset()
JLINK_TIF_ReleaseTargetReset()
JLINK_TIF_SetSpeed()
JLINK_TIF_SetClrTCK()
JLINK_TIF_SetClrTMS()
JLINK_TIF_SetClrTDI()
6.20
3
171006
NG
Chapter “Working with J-Link and J-Trace”
* Section “Script file API functions”: Added return values for various functions
6.20
2
171005
EL
Chapter “Open Flashloader”
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
7
Manual
Revision
version
Date
By
Description
* Section “Add. Info / Considerations / Limitations”: Updated
6.20
1
170922
NG
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Command Strings”: Updated
Added new command string “EnableLowPowerHandlingMode”
6.16
0
170320
EL
Chapter “Open Flashloader”
Added “AlwaysPresent” as new attribute to the
6.14
6
170407
NV
Chapter “Working with J-Link and J-Trace”
* Section “J-Link scriptfiles”: Updated
“JLINK_ExecCommand()” description
6.14
5
170320
EL
Chapter “J-Flash SPI”
Updated screenshots
NV
Chapter “Working with J-Link and J-Trace”
* Section “J-Link scriptfiles”:
Added: “JLINK_ExecCommand()”
Section “Keil MDK-ARM” added for Command string execution
NV
Chapter “Working with J-Link and J-Trace”
* Section “J-Link scriptfiles”:
Added: “OnTraceStart()” and “JLINK_TRACE_Portwidth”
Chapter “Trace”
* Added crossreference to “JLINK_TRACE_Portwidth”
NV
Chapter “Introduction”
*Added Subsubsection “Software and Hardware
Features Overview” to all device Subsections.
*Edited Subsection “”J-Trace ARM.
*Section “Target interfaces and adapters”:
edited “RESET” to “nRESET” and updated description.
NV
Chapter “Working with J-Link and J-Trace”
* Section “Exec Commands”: Updated
SetResetPulseLen
TraceSampleAdjust
Chapter “Trace”
* Section “Tracing via trace pins”: Updated
6.14
6.14
6.14
6.14
4
3
2
1
170317
170220
170216
170210
6.14
0
170201
AG
Chapter “Working with J-Link”
* Section “Exec Commands”: Updated
SelectTraceSource
SetRAWTRACEPinDelay
ReadIntoTraceCache
Chapter “Trace” added.
6.10a
0
160820
EL
Chapter “Working With J-Link”
* Section “Exec Commands”: Updated ExcludeFlashCacheRanges.
6.00i
0
160802
EL
Chapter “Introduction”
* Removed “Model Feature Lists”
Chapter “Adding Support for New Devices”:
renamed to “Open Flash Loader”
Chapter “Open Flash Loader” updated.
6.00
1
160617
EL
Chapter “J-Flash SPI”
* Added chapter “Custom Command Sequences”
6.00
0
160519
AG
Chapter “Adding Support for New Devices” added.
5.12f
0
160503
AB
Chapter “Related Software”
* Section “J-Link RTT Viewer” updated and moved from section “RTT”.
5.12d
1
160427
AG
Chapter “Working with J-Link and J-Trace”
* Section “J-Link script files” updated.
5.12d
0
160425
AG
Chapter “Working with J-Link and J-Trace”
* Section “J-Link script files” updated.
5.12c
0
160413
NG
Chapter “Related Software”
* Section “J-Link Commander”
Typo fixed.
NG
Chapter “Related Software”
* Section “J-Link Commander”
Commands and commandline options added.
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Command Strings”
Command “SetRTTTelnetPort” added.
5.12c
1
J-Link / J-Trace (UM08001)
160418
© 2004-2021 SEGGER Microcontroller GmbH
8
Manual
Revision
version
Date
By
Description
Chapter “Flash Download”
* Section “Debugging applications that change flash contents at runtime”
added.
5.10u
0
160317
AG
Chapter “Monitor Mode Debugging”
* Section “Target application performs reset” added.
5.10t
0
160314
AG
Chapter “Monitor Mode Debugging”
* Section “Enable Monitor Debugging” updated.
* Section “Forwarding of Monitor Interrupts” added.
5.10
3
160309
EL
Chapter “J-Flash SPI” updated.
5.10
2
160215
AG
Chapter “RTT” updated.
5.10
1
151204
AG
Chapter “RDI” updated.
Chapter “Semihosting” added.
5.10
0
151127
NG
Chapter “Related Software”
* Section “J-Scope” removed.
5.02m
0
151125
AG
Chapter “Working with J-Link and J-Trace”
* Section “The J-Link settings file” added.
Chapter “Low Power Debugging” added.
5.02l
0
151123
AG
Various Chapters
* Some typos corrected.
5.02i
1
151106
RH
Chapter “J-Flash SPI”
* Section “Send custom commands” added.
5.02i
0
151105
RH
Chapter “Related Software”
* Section “J-Link Commander”
exec command added.
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Command Strings”
New commands added.
5.02f
1
151022
NG
Chapter “Related Software”
* Section “J-Scope” updated.
5.02f
1
151022
EL
Chapter “Target interfaces and adapters”
* Section “Reference voltage (VTref)” added.
5.02f
0
151007
RH
Chapter “Working with J-Link and J-Trace”
* Section “J-Link script files” updated.
5.02e
0
151001
AG
Chapter “Working with J-Link and J-Trace”
* Section “J-Link script files” updated
5.02c
1
150925
NG
Chapter “Licensing”
* Section “Original SEGGER products” updated.
Chapter “Flash download”
* Section “Setup for various debuggers (CFI flash)” updated.
5.02c
0
150916
RH
Chapter “Flash download”
* Section “Setup for various debuggers (SPIFI flash)” added.
5.02c
0
150914
RH
Chapter “Introduction”
* Section “J-Link / J-Trace models” updated.
* Section “Supported OS”
Added Windows 10
5.02a
0
150903
AG
Chapter “Monitor Mode Debugging” added.
5.02
0
150820
AG
Chapter “Working with J-Link and J-Trace”
* Section “J-Link Command Strings”
“DisableCortexMXPSRAutoCorrectTBit” added.
5.02
0
150813
AG
Chapter “Monitor Mode Debugging” added.
5.00
1
150728
NG
Chapter “Related Software”
* Section “J-Link Commander”
Sub-Section “Command line options” updated.
5.00
0
150609
AG
Chapter “Flash download”
* Section “QSPI flash support” added.
Chapter “Flash breakpoints”
* Section “Flash Breakpoints in QSPI flash” added
5.00
0
150520
EL
Chapter “J-Flash SPI”
* Initial version added
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
9
Manual
Revision
version
Date
By
Description
4.99b
0
150520
EL
Chapter “Related Software”
* Section “J-Link STM32 Unlock”
Added command line options
4.99a
0
150429
AG
Chapter “Target interfaces and Adapters”
Chapter “20-pin J-Link connector”, section “Pinout for SPI” added.
4.98d
0
150427
EL
Chapter “Related Software”
* Section “Configure SWO output after device reset” updated.
4.98b
0
150410
AG
Chapter “Licensing”
* Section “J-Trace for Cortex-M” updated.
4.98
0
150320
NG
Chapter “Related Software”
* Section “J-Link Commander”
Sub-Section “Commands” added.
Chapter “Working with J-Link and J-Trace”
* Section “J-Link script files” updated
4.96f
0
150204
JL
Chapter “Related Software”
* Section “GDB Server”
Exit code description added.
4.96
0
141219
JL
Chapter “RTT” added.
Chapter “Related Software”
* Section “GDB Server”
Command line option “-strict” added.
Command line option “-timeout” added.
4.90d
0
141112
NG
Chapter “Related Software”
* Section “J-Link Remote Server” updated.
* Section “J-Scope” updated.
4.90c
0
140924
JL
Chapter “Related Software”
* Section “JTAGLoad” updated.
4.90b
1
140813
EL
Chapter “Working with J-Link and J-Trace”
* Section “Connecting multiple J-Links / J-Traces to your PC” updated
Chapter “J-Link software”
* Section “J-Link Configurator” updated.
4.90b
0
140813
NG
Chapter “Related Software”
* Section “J-Scope” added.
4.86
2
140606
AG
Chapter “Device specifics”
* Section “Silicon Labs - EFM32 series devices” added
4.86
1
140527
JL
Chapter “Related Software”
* Section “GDB Server”
Command line options -halt / -nohalt added.
Description for GDB Server CL version added.
4.86
0
140519
AG
Chapter “Flash download”
Section “Mentor Sourcery CodeBench” added.
EL
Chapter “Working with J-Link”
* Section “Virtual COM Port (VCOM) improved.
Chapter ”Target interfaces and adapters“
* Section ”Pinout for SWD + Virtual COM Port (VCOM) added.“
4.84
0
140321
4.82
1
140228
EL
Chapter ”Related Software“
* Section ”Command line options“
Extended command line option -speed.
Chapter ”J-Link software and documentation package“
* Section ”J-Link STR91x Commander“
Added command line option parameter to specify a customized
scan-chain.
Chapter ”Working with J-Link“
* Section ”Virtual COM Port (VCOM) added.
Chapter “Setup”
* Section “Getting started with J-Link and DS-5”
4.82
0
140218
JL
Chapter “Related Software”
* Section “GDB Server”
Command line option -notimeout added.
4.80f
0
140204
JL
Chapter “Related Software”
* Section “GDB Server”
Command line options and remote commands added.
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
10
Manual
Revision
version
Date
By
Description
Chapter “Related Software”
* Section “GDB Server”
Remote commands and command line options description improved.
Several corrections.
4.80
1
131219
JL/
NG
4.80
0
131105
JL
Chapter “Related Software”
* Section “GDB Server”
SEGGER-specific GDB protocol extensions added.
4.76
3
130823
JL
Chapter “Flash Download”
* Replaced references to GDB Server manual.
Chapter “Working with J-Link”
* Replaced references to GDB Server manual.
4.76
2
130821
JL
Chapter “Related Software”
* Section “GDB Server”
Remote commands added.
4.76
1
130819
JL
Chapter “Related Software”
* Section “SWO Viewer”
Sample code updated.
4.76
0
130809
JL
Chapter “Related Software”
* Sections reordered and updated.
Chapter “Setup”
* Section “Using JLinkARM.dll moved here.
4.71b
0
130507
JL
Chapter ”Related Software“
* Section ”SWO Viewer“
Added new command line options.
4.66
0
130221
JL
Chapter ”Introduction“
* Section ”Supported OS“
Added Linux and Mac OSX
4.62b
0
130219
EL
Chapter ”Introduction“
* Section ”J-Link / J-Trace models“
Clock rise and fall times updated.
4.62
0
130129
JL
Chapter ”Introduction“
* Section ”J-Link / J-Trace models“
Sub-section ”J-link ULTRA“ updated.
4.62
0
130124
EL
Chapter ”Target interfaces and adapters“
* Section ”9-pin JTAG/SWD connector“
Pinout description corrected.
4.58
1
121206
AG
Chapter ”Introduction“
* Section ”J-Link / J-Trace models“ updated.
4.58
0
121126
JL
Chapter ”Working with J-Link“
* Section ”J-Link script files“
Sub-section ”Executing J-Link script files“ updated.
4.56b
0
121112
JL
Chapter ”Related Software“
* Section ”J-Link SWO Viewer“
Added sub-section ”Configure SWO output after device reset“
4.56a
0
121106
JL
Chapter ”Related Software“
* Section ”J-Link Commander“
Renamed ”Commander script files“ to ”Commander files“ and
”script mode“ to ”batch mode“.
4.56
0
121022
AG
Renamed ”J-Link TCP/IP Server“ to ”J-Link Remote Server“
4.54
1
121009
JL
Chapter ”Related Software“
* Section ”TCP/IP Server“, subsection ”Tunneling Mode“ added.
4.54
0
120913
EL
Chapter ”Flash Breakpoints“
* Section ”Licensing“ updated.
Chapter ”Device specifics“
* Section ”Freescale“, subsection ”Data flash support“ added.
4.53c
0
120904
EL
Chapter ”Licensing“
* Section ”Device-based license“ updated.
EL
Chapter ”Flash download“
* Section ”J-Link commander“ updated.
Chapter ”Support and FAQs“
* Section ”Frequently asked questions“ updated.
Chapter ”J-Link and J-Trace related software“
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* Section ”J-Link Commander“ updated.
4.51e
1
120704
EL
Chapter ”Working with J-Link“
* Section ”Reset strategies“ updated and corrected. Added reset type 8.
4.51e
0
120704
AG
Chapter ”Device specifics“
* Section ”ST“ updated and corrected.
4.51b
0
120611
EL
Chapter ”J-Link and J-Trace related software“
* Section ”SWO Viewer“ added.
4.51a
0
120606
EL
Chapter ”Device specifics“
* Section ”ST“, subsection ”ETM init“ for some STM32 devices added.
* Section ”Texas Instruments“ updated.
Chapter ”Target interfaces and adapters“
* Section ”Pinout for SWD“ updated.
4.47a
0
120419
AG
Chapter ”Device specifics“
* Section ”Texas Instruments“ updated.
4.46
0
120416
EL
Chapter ”Support“ updated.
4.42
0
120214
EL
Chapter ”Working with J-Link“
* Section ”J-Link script files“ updated.
4.36
1
110927
EL
Chapter ”Flash download“ added.
Chapter ”Flash breakpoints“ added.
Chapter ”Target interfaces and adapters“
* Section ”20-pin JTAG/SWD connector“ updated.
Chapter ”RDI“ added.
Chapter ”Setup“ updated.
Chapter ”Device specifics“ updated.
4.36
0
110909
AG
Chapter ”Working with J-Link“
* Section ”J-Link script files“ updated.
4.26
1
110513
KN
Chapter ”Introduction“
* Section ”J-Link / J-Trace models“ corrected.
4.26
0
110427
KN
Several corrections.
AG
Chapter ”Introduction“
* Section ”J-Link / J-Trace models“ corrected.
Chapter ”Device specifics“
* Section ”ST Microelectronics“ updated.
4.24
1
110228
4.24
0
110216
AG
Chapter ”Device specifics“
* Section ”Samsung“ added.
Chapter ”Working with J-Link“
* Section ”Reset strategies“ updated.
Chapter ”Target interfaces and adapters“
* Section ”9-pin JTAG/SWD connector“ added.
4.23d
0
110202
AG
Chapter ”J-Link and J-Trace related software“
* Section ”J-Link software and documentation package in detail“ updated.
Chapter ”Introduction“
* Section ”Built-in intelligence for supported CPU-cores“ added.
4.21g
0
101130
AG
Chapter ”Working with J-Link“
* Section ”Reset strategies“ updated.
Chapter ”Device specifics“
* Section ”Freescale“ updated.
Chapter ”Flash download and flash breakpoints
* Section “Supported devices” updated
* Section “Setup for different debuggers (CFI flash)” updated.
4.21
0
101025
AG
Chapter “Device specifics”
* Section “Freescale” updated.
4.20j
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101019
AG
Chapter “Working with J-Link”
* Section “Reset strategies” updated.
4.20b
0
100923
AG
Chapter “Working with J-Link”
* Section “Reset strategies” updated.
AG
Chapter “Working with J-Link”
* Section “J-Link script files” updated.
* Section “J-Link Command Strings” updated.
Chapter “Target interfaces and adapters”
* Section “19-pin JTAG/SWD and Trace connector” corrected.
Chapter “Setup”
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Several corrections.
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Chapter “J-Link and J-Trace related software”
* Section “SWO Analyzer” added.
0.00
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100617
AG
Several corrections.
0.00
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100504
AG
Chapter “Introduction”
* Section “J-Link / J-Trace models” updated.
Chapter “Target interfaces and adapters”
* Section “Adapters” updated.
0.00
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100428
AG
Chapter “Introduction”
* Section “J-Link / J-Trace models” updated.
0.00
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100324
KN
Chapter “Working with J-Link and J-Trace”
* Several corrections
Chapter Flash download & flash breakpoints
* Section “Supported devices” updated
0.00
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Chapter “Introduction”
* Section “J-Link / J-Trace models” updated.
0.00
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Chapter “Working with J-Link”
* Section “J-Link script files” added.
0.00
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100202
KN
Chapter “Device Specifics”
* Section “Luminary Micro” updated.
Chapter “Flash download and flash breakpoints”
* Section “Supported devices” updated.
0.00
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100104
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Chapter “Flash download and flash breakpoints
* Section ”Supported devices“ updated
0.00
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091201
AG
Chapter ”Working with J-Link and J-Trace“
* Section ”Reset strategies“ updated.
Chapter ”Licensing“
* Section ”J-Link OEM versions“ updated.
0.00
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AG
Chapter ”Licensing“
* Section ”J-Link OEM versions“ updated.
0.00
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090910
AG
Chapter ”Introduction“
* Section ”J-Link / J-Trace models“ updated.
KN
Chapter ”Introduction“
* Section” Specifications“ updated
* Section ”Hardware versions“ updated
* Section ”Common features of the J-Link product family“ updated
Chapter ”Target interfaces and adapters“
* Section ”5 Volt adapter“ updated
AG
Chapter ”Introduction“
* Section ”J-Link / J-Trace models“ updated.
Chapter ”Working with J-Link and J-Trace“
* Section ”SWD interface“ updated.
KN
Chapter ”Introduction“
* Section ”Supported IDEs“ added
* Section ”Supported CPU cores“ updated
* Section ”Model comparison chart“ renamed to
”Model comparison“
* Section ”J-Link bundle comparison chart“ removed
KN
Chapter ”Introduction“
* Section ”J-Link and J-Trace models“ added
* Sections ”Model comparison chart“ &
”J-Link bundle comparison chart“added
Chapter ”J-Link and J-Trace models“ removed
Chapter ”Hardware“ renamed to ”Target interfaces & adapters“
* Section ”JTAG Isolator“ added
Chapter ”Target interfaces and adapters“
* Section ”Target board design“ updated
Several corrections
AG
Chapter ”Working with J-Link“
* Section ”J-Link control panel“ updated.
Chapter ”Flash download and flash breakpoints“
* Section ”Supported devices“ updated.
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Chapter ”Device specifics“
* Section ”NXP“ updated.
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Chapter ”Device specifics“
* Section ”NXP“ updated.
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090605
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Chapter ”Introduction“
* Section ”Common features of the J-Link
product family“ updated.
AG
Chapter ”Working with J-Link“
* Section ”Reset strategies“ updated.
* Section ”Indicators“ updated.
Chapter ”Flash download and flash breakpoints“
* Section ”Supported devices“ updated.
0.00
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090515
0.00
68
090428
AG
Chapter ”J-Link and J-Trace related software“
* Section ”J-Link STM32 Commander“ added.
Chapter ”Working with J-Link“
* Section ”Reset strategies“ updated.
0.00
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090402
AG
Chapter ”Working with J-Link“
* Section ”Reset strategies“ updated.
0.00
66
090327
AG
Chapter ”Background information“
* Section ”Embedded Trace Macrocell (ETM)“ updated.
Chapter ”J-Link and J-Trace related software“
* Section ”Dedicated flash programming utilities for J-Link“ updated.
0.00
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090320
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Several changes in the manual structure.
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090313
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Chapter ”Working with J-Link“
* Section ”Indicators“ added.
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090212
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Chapter ”Hardware“
* Several corrections.
* Section ”Hardware Versions“ Version 8.0 added.
0.00
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090211
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Chapter ”Working with J-Link and J-Trace“
* Section ”Reset strategies“ updated.
Chapter J-Link and J-Trace related software
* Section ”J-Link STR91x Commander (Command line tool)“ updated.
Chapter ”Device specifics“
* Section ”ST Microelectronics“ updated.
Chapter ”Hardware“ updated.
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Chapter ”Working with J-Link“
* Section ”Cortex-M3 specific reset strategies“
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Chapter ”Working with J-Link“
* Section ”Cortex-M3 specific reset strategies“
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090108
KN
Chapter Hardware
* Section ”Target board design for JTAG“ updated.
* Section ”Target board design for SWD“ added.
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090105
AG
Chapter ”Working with J-Link Pro“
* Section ”Connecting J-Link Pro the first time“ updated.
AG
Chapter ”Working with J-Link Pro“
* Section ”Introduction“ updated.
* Section ”Configuring J-Link Pro via web interface“ updated.
Chapter ”Introduction“
* Section ”J-Link Pro overview“ updated.
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Chapter ”Working with J-Link Pro“
* Section ”FAQs“ added.
Chapter ”Support and FAQs“
* Section ”Frequently Asked Questions“ updated.
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AG
Chapter ”Hardware“ updated.
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Chapter ”Working with J-Link and J-Trace“
* Section ”J-Link Command Strings“ updated.
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Chapter ”Working with J-Link Pro“ updated.
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Chapter ”Working with J-Link Pro“ added.
Chapter ”Licensing“
* Section ”Original SEGGER products“ updated.
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Several corrections.
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Chapter ”Flash download and flash breakpoints“
* Section ”Supported devices“ corrected.
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081029
AG
Several corrections.
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080916
AG
Chapter ”Working with J-Link and J-Trace“
* Section ”Connecting multiple J-Links /
J-Traces to your PC“ updated.
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080910
AG
Chapter ”Licensing“ updated.
0.00
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080904
AG
Chapter ”Licensing“ added.
Chapter ”Hardware“
Section ”J-Link OEM versions“ moved to chapter ”Licensing“
0.00
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080902
AG
Chapter ”Hardware“
Section ”JTAG+Trace connector“ JTAG+Trace
connector pinout corrected.
Section ”J-Link OEM versions“ updated.
0.00
44
080827
AG
Chapter ”J-Link control panel“ moved to chapter ”Working with J-Link“.
Several corrections.
0.00
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080826
AG
Chapter ”Flash download and flash breakpoints“
Section ”Supported devices“ updated.
0.00
42
080820
AG
Chapter ”Flash download and flash breakpoints“
Section ”Supported devices“ updated.
0.00
41
080811
AG
Chapter ”Flash download and flash breakpoints“ updated.
Chapter ”Flash download and flash breakpoints“,
section ”Supported devices“ updated.
0.00
40
080630
AG
Chapter ”Flash download and flash breakpoints“ updated.
Chapter ”J-Link status window“ renamed to ”J-Link control panel“
Various corrections.
AG
Chapter ”Flash download and flash breakpoints“
Section ”Licensing“ updated.
Section ”Using flash download and flash
breakpoints with different debuggers“ updated.
Chapter ”J-Link status window“ added.
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080627
0.00
38
080618
AG
Chapter ”Support and FAQs“
Section ”Frequently Asked Questions“ updated
Chapter ”Reset strategies“
Section ”Cortex-M3 specific reset strategies“ updated.
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080617
AG
Chapter ”Reset strategies“
Section ”Cortex-M3 specific reset strategies“ updated.
0.00
36
080530
AG
Chapter ”Hardware“
Section ”Differences between different versions“ updated.
Chapter ”Working with J-Link and J-Trace“
Section ”Cortex-M3 specific reset strategies“ added.
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35
080215
AG
Chapter ”J-Link and J-Trace related software“
Section ”J-Link software and documentation package in detail“ updated.
0.00
34
080212
AG
Chapter ”J-Link and J-Trace related software“
Section ”J-Link TCP/IP Server (Remote J-Link / J-Trace use)“ updated.
Chapter ”Working with J-Link and J-Trace“
Section ”J-Link Command Strings“ updated.
Chapter ”Flash download and flash breakpoints“
Section ”Introduction“ updated.
Section ”Licensing“ updated.
Section ”Using flash download and flash breakpoints with
different debuggers“ updated.
0.00
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080207
AG
Chapter ”Flash download and flash breakpoints“ added
Chapter ”Device specifics:“
Section ”ATMEL - AT91SAM7 - Recommended init sequence“ added.
0.00
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080129
SK
Chapter ”Device specifics“:
Section ”NXP - LPC - Fast GPIO bug“ list of device enhanced.
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080103
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Chapter ”Device specifics“:
Section ”NXP - LPC - Fast GPIO bug“ updated.
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071211
AG
Chapter ”Device specifics“:
Section ”Analog Devices“ updated.
Section ”ATMEL“ updated.
J-Link / J-Trace (UM08001)
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Manual
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version
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Description
Section ”Freescale“ added.
Section ”Luminary Micro“ added.
Section ”NXP“ updated.
Section ”OKI“ added.
Section ”ST Microelectronics“ updated.
Section ”Texas Instruments“ updated.
Chapter ”Related software“:
Section ”J-Link STR91x Commander“ updated
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070912
SK
Chapter ”Hardware“, section ”Target board design“ updated.
0.00
28
070912
SK
Chapter ”Related software“:
Section ”J-LinkSTR91x Commander“ added.
Chapter ”Device specifics“:
Section ”ST Microelectronics“ added.
Section ”Texas Instruments“ added.
Subsection ”AT91SAM9“ added.
0.00
28
070912
AG
Chapter ”Working with J-Link/J-Trace“:
Section ”J-Link Command Strings“ updated.
0.00
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070827
TQ
Chapter ”Working with J-Link/J-Trace“:
Section ”J-Link Command Strings“ updated.
SK
Chapter ”Introduction“:
Section ”Features of J-Link“ updated.
Chapter ”Background Information“:
Section ”Embedded Trace Macrocell“ added.
Section ”Embedded Trace Buffer“ added.
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070516
SK
Chapter ”Working with J-Link/J-Trace“:
Section ”Reset strategies in detail“
- ”Software, for Analog Devices ADuC7xxx MCUs“ updated
- ”Software, for ATMEL AT91SAM7 MCUs“ added.
Chapter ”Device specifics“
Section ”Analog Devices“ added.
Section ”ATMEL“ added.
0.00
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070323
SK
Chapter ”Setup“:
”Uninstalling the J-Link driver“ updated.
”Supported ARM cores“ updated.
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070320
SK
Chapter ”Hardware“:
”Using the JTAG connector with SWD“ updated.
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Chapter ”Hardware“:
”Using the JTAG connector with SWD“ added.
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070312
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Chapter ”Hardware“:
”Differences between different versions“ supplemented.
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070307
SK
Chapter ”J-Link / J-Trace related software“:
”J-Link GDB Server“ licensing updated.
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070226
SK
Chapter ”J-Link / J-Trace related software“ updated and reorganized.
Chapter ”Hardware“
”List of OEM products“ updated
0.00
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070221
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Chapter ”Device specifics“ added
Subchapter ”J-Link Command Strings“ added
0.00
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070131
SK
Chapter ”Hardware“:
”Version 5.3“: Current limits added
”Version 5.4“ added
Chapter ”Setup“:
”Installing the J-Link USB driver“ removed.
”Installing the J-Link software and documentation pack“ added.
Subchapter ”List of OEM products“ updated.
”OS support“ updated
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061222
SK
Chapter ”Preface“: ”Company description“ added.
J-Link picture changed.
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060914
OO
Subchapter 1.5.1: Added target supply voltage and target supply current
to specifications.
Subchapter 5.2.1: Pictures of ways to connect J-Trace.
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Subchapter 4.7 ”Using DCC for memory reads“ added.
0.00
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060711
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Subchapter 5.2.2: Corrected JTAG+Trace connector pinout table.
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Subchapter 4.1: Added ARM966E-S to List of supported ARM cores.
0.00
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060607
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Subchapter 5.5.2.2 changed.
Subchapter 5.5.2.3 added.
SK
ARM9 download speed updated.
Subchapter 8.2.1: Screenshot ”Start sequence“ updated.
Subchapter 8.2.2 ”ID sequence“ removed.
Chapter ”Support“ and ”FAQ“ merged.
Various improvements
0.00
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060526
0.00
9
060324
OO
Chapter ”Literature and references“ added.
Chapter ”Hardware“:
Added common information trace signals.
Added timing diagram for trace.
Chapter ”Designing the target board for trace“ added.
0.00
8
060117
OO
Chapter ”Related Software“: Added JLinkARM.dll.
Screenshots updated.
0.00
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051208
OO
Chapter Working with J-Link: Sketch added.
0.00
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051118
OO
Chapter Working with J-Link: ”Connecting multiple J-Links to your PC“
added.
Chapter Working with J-Link: ”Multi core debugging“ added.
Chapter Background information: ”J-Link firmware“ added.
0.00
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051103
TQ
Chapter Setup: ”JTAG Speed“ added.
0.00
4
051025
OO
Chapter Background information: ”Flash programming“ added.
Chapter Setup: ”Scan chain configuration“ added.
Some smaller changes.
0.00
3
051021
TQ
Performance values updated.
0.00
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051011
TQ
Chapter ”Working with J-Link“ added.
0.00
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050818
TW
Initial Version
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
17
About this document
Assumptions
This document assumes that you already have a solid knowledge of the following:
•
•
•
•
The software tools used for building your application (assembler, linker, C compiler).
The C programming language.
The target processor.
DOS command line.
If you feel that your knowledge of C is not sufficient, we recommend The C Programming Language by Kernighan and Richie (ISBN 0--13--1103628), which describes the standard in C programming and, in newer editions, also covers the ANSI C standard.
How to use this manual
This manual explains all the functions and macros that the product offers. It assumes you have
a working knowledge of the C language. Knowledge of assembly programming is not required.
Typographic conventions for syntax
This manual uses the following typographic conventions:
Style
Used for
Body
Body text.
Keyword
Text that you enter at the command prompt or that appears on
the display (that is system functions, file- or pathnames).
Parameter
Parameters in API functions.
Sample
Sample code in program examples.
Sample comment
Comments in program examples.
Reference
Reference to chapters, sections, tables and figures or other documents.
GUIElement
Buttons, dialog boxes, menu names, menu commands.
Emphasis
Very important sections.
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
18
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
19
Table of contents
1
Introduction ..................................................................................................................28
1.1
1.2
1.3
1.4
1.5
1.6
2
Licensing ..................................................................................................................... 36
2.1
2.2
2.3
3
Requirements .............................................................................................. 29
Supported OS .............................................................................................. 30
Common features of the J-Link product family ................................................. 31
Supported CPU cores ....................................................................................32
Built-in intelligence for supported CPU-cores ....................................................33
1.5.1 Intelligence in the J-Link firmware ...................................................... 33
1.5.2 Intelligence on the PC-side (DLL) ........................................................ 33
1.5.3 Firmware intelligence per model ..........................................................34
Where to find further information ...................................................................35
1.6.1 SEGGER debug probes .......................................................................35
1.6.2 Using a feature in a specific development environment .......................... 35
Components requiring a license ..................................................................... 37
Legal use of SEGGER J-Link software ............................................................. 38
2.2.1 Use of the software with 3rd party tools .............................................. 38
Illegal Clones ...............................................................................................39
J-Link software and documentation package ............................................................. 40
3.1
3.2
3.3
3.4
3.5
3.6
3.7
Software overview ........................................................................................41
J-Link Commander (Command line tool) ......................................................... 42
3.2.1 Command line options ....................................................................... 42
3.2.2 Using J-Link Command Files ............................................................... 42
J-Link Remote Server ................................................................................... 43
3.3.1 List of available commands ................................................................ 43
3.3.2 Tunneling mode ................................................................................ 44
3.3.3 Connecting to J-Link/ J-Trace using J-Link Remote Server ....................... 45
3.3.4 Encrypted connection .........................................................................47
J-Mem Memory Viewer ................................................................................. 48
J-Flash ........................................................................................................ 49
J-Flash Lite ................................................................................................. 50
3.6.1 Limitations in comparison to J-Flash .................................................... 50
3.6.2 Usage .............................................................................................. 50
J-Link RTT Viewer ........................................................................................ 52
3.7.1 RTT Viewer Startup ........................................................................... 52
3.7.2 Connection Settings ...........................................................................53
3.7.3 The Terminal Tabs ............................................................................. 53
3.7.4 Sending Input ...................................................................................54
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
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3.8
3.9
3.10
3.11
3.12
3.13
4
3.7.5 Logging Terminal output .................................................................... 54
3.7.6 Logging Data .................................................................................... 54
3.7.7 Command line options ....................................................................... 55
3.7.8 Menus and Shortcuts ......................................................................... 57
3.7.9 Using "virtual" Terminals in RTT .......................................................... 59
3.7.10 Using Text Control Codes ................................................................. 59
J-Link SWO Viewer .......................................................................................60
3.8.1 J-Link SWO Viewer CL ....................................................................... 60
3.8.2 Usage .............................................................................................. 61
3.8.3 List of available command line options .................................................61
3.8.4 Configure SWO output after device reset ..............................................63
3.8.5 Target example code for terminal output .............................................. 64
SWO Analyzer ..............................................................................................66
JTAGLoad (Command line tool) .................................................................... 67
J-Link RDI (Remote Debug Interface) ........................................................... 69
3.11.1 Flash download and flash breakpoints ................................................ 69
Processor specific tools ............................................................................... 70
3.12.1 J-Link STR91x Commander (Command line tool) ................................. 70
3.12.2 J-Link STM32 Unlock (Command line tool) .......................................... 73
J-Link Software Developer Kit (SDK) .............................................................76
J-Link GDB Server ......................................................................................................77
4.1
4.2
4.3
J-Link GDB Server CL (Windows, Linux, Mac) .................................................. 79
Debugging with J-Link GDB Server .................................................................80
4.2.1 Setting up GDB Server GUI version ..................................................... 80
4.2.2 Setting up GDB Server CL version .......................................................80
4.2.3 GDB Server user interface ..................................................................81
4.2.4 Running GDB from different programs ................................................. 82
Supported remote (monitor) commands ..........................................................85
4.3.1 clrbp ................................................................................................86
4.3.2 cp15 ................................................................................................ 87
4.3.3 device ..............................................................................................87
4.3.4 DisableChecks ...................................................................................87
4.3.5 EnableChecks ................................................................................... 88
4.3.6 flash breakpoints ...............................................................................88
4.3.7 flash erase ....................................................................................... 88
4.3.8 getargs ............................................................................................ 88
4.3.9 go ................................................................................................... 88
4.3.10 halt ............................................................................................... 89
4.3.11 interface .........................................................................................89
4.3.12 jtagconf ..........................................................................................89
4.3.13 memU8 .......................................................................................... 90
4.3.14 memU16 ........................................................................................ 90
4.3.15 memU32 ........................................................................................ 90
4.3.16 reg ................................................................................................ 91
4.3.17 regs ...............................................................................................91
4.3.18 reset ..............................................................................................91
4.3.19 semihosting breakOnError ................................................................ 92
4.3.20 semihosting enable ..........................................................................92
4.3.21 semihosting IOClient ........................................................................92
4.3.22 semihosting ARMSWI ....................................................................... 93
4.3.23 semihosting ThumbSWI ....................................................................93
4.3.24 setargs ...........................................................................................93
4.3.25 setbp ............................................................................................. 94
4.3.26 sleep ..............................................................................................94
4.3.27 speed .............................................................................................94
4.3.28 step ............................................................................................... 95
4.3.29 SWO DisableTarget .......................................................................... 95
4.3.30 SWO EnableTarget ........................................................................... 95
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© 2004-2021 SEGGER Microcontroller GmbH
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4.4
4.5
4.6
4.7
5
4.3.31 SWO GetMaxSpeed ..........................................................................96
4.3.32 SWO GetSpeedInfo .......................................................................... 96
4.3.33 waithalt .......................................................................................... 96
4.3.34 wice ...............................................................................................97
4.3.35 ReadAP .......................................................................................... 97
4.3.36 ReadDP .......................................................................................... 97
4.3.37 WriteAP .......................................................................................... 98
4.3.38 WriteDP ..........................................................................................98
SEGGER-specific GDB protocol extensions ..................................................... 100
Command line options ................................................................................ 101
4.5.1 -cpu ...............................................................................................102
4.5.2 -device ...........................................................................................103
4.5.3 -endian .......................................................................................... 103
4.5.4 -gui ............................................................................................... 104
4.5.5 -if ..................................................................................................104
4.5.6 -ir ..................................................................................................104
4.5.7 -excdbg ..........................................................................................104
4.5.8 -jtagconf ........................................................................................ 105
4.5.9 -localhostonly ..................................................................................105
4.5.10 -log ..............................................................................................105
4.5.11 -logtofile .......................................................................................106
4.5.12 -halt .............................................................................................106
4.5.13 -nogui .......................................................................................... 106
4.5.14 -noir ............................................................................................ 106
4.5.15 -nolocalhostonly ............................................................................ 107
4.5.16 -nologtofile ................................................................................... 107
4.5.17 -nohalt ......................................................................................... 107
4.5.18 -noreset ....................................................................................... 108
4.5.19 -nosinglerun ..................................................................................108
4.5.20 -nosilent ....................................................................................... 108
4.5.21 -nostayontop .................................................................................108
4.5.22 -notimeout ....................................................................................109
4.5.23 -novd ........................................................................................... 109
4.5.24 -port ............................................................................................ 109
4.5.25 -rtos ............................................................................................ 109
4.5.26 -JLinkDevicesXMLPath .................................................................... 110
4.5.27 -jlinkscriptfile ................................................................................ 110
4.5.28 -powertarget ................................................................................. 110
4.5.29 -select ..........................................................................................110
4.5.30 -settingsfile ...................................................................................111
4.5.31 -silent .......................................................................................... 111
4.5.32 -singlerun ..................................................................................... 111
4.5.33 -speed ..........................................................................................111
4.5.34 -stayontop .................................................................................... 112
4.5.35 -timeout ....................................................................................... 112
4.5.36 -strict ........................................................................................... 112
4.5.37 -swoport .......................................................................................113
4.5.38 -telnetport .................................................................................... 113
4.5.39 -vd .............................................................................................. 113
4.5.40 -x ................................................................................................ 113
4.5.41 -xc ...............................................................................................114
Program termination ................................................................................... 115
4.6.1 Exit codes ...................................................................................... 115
Semihosting ...............................................................................................116
J-Mem ....................................................................................................................... 117
5.1
5.2
Setting up J-Mem .......................................................................................118
J-Mem user interface .................................................................................. 119
5.2.1 Go To .............................................................................................119
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© 2004-2021 SEGGER Microcontroller GmbH
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5.2.2
5.2.3
5.2.4
5.2.5
5.2.6
6
Setup ......................................................................................................................... 122
6.1
6.2
6.3
6.4
6.5
6.6
6.7
7
Access width ...................................................................................119
Fill memory .................................................................................... 119
Save memory data .......................................................................... 120
Periodic Refresh .............................................................................. 120
Command line options ..................................................................... 121
Installing the J-Link software and documentation pack .................................... 123
6.1.1 Setup procedure ..............................................................................123
Setting up the USB interface ....................................................................... 124
6.2.1 Verifying correct driver installation .....................................................124
6.2.2 Uninstalling the J-Link USB driver ......................................................125
Setting up the IP interface .......................................................................... 127
6.3.1 Configuring J-Link using J-Link Configurator ........................................127
6.3.2 Configuring J-Link using the webinterface ........................................... 127
FAQs ......................................................................................................... 129
J-Link Configurator ..................................................................................... 130
6.5.1 Configure J-Links using the J-Link Configurator ................................... 130
J-Link USB identification ..............................................................................132
6.6.1 Connecting to different J-Links connected to the same host PC via USB ... 132
Using the J-Link DLL ...................................................................................133
6.7.1 What is the JLink DLL? .................................................................... 133
6.7.2 Updating the DLL in third-party programs ...........................................133
6.7.3 Determining the version of JLink DLL ................................................. 133
6.7.4 Determining which DLL is used by a program ......................................134
Working with J-Link and J-Trace .............................................................................. 135
7.1
7.2
7.3
J-Link WiFi setup ........................................................................................136
Supported IDEs ..........................................................................................137
Connecting the target system ...................................................................... 138
7.3.1 Power-on sequence ..........................................................................138
7.3.2 Verifying target device connection ..................................................... 138
7.3.3 Problems ........................................................................................ 138
7.4 Indicators .................................................................................................. 139
7.4.1 Main indicator ................................................................................. 139
7.4.2 Input indicator ................................................................................ 139
7.4.3 Output indicator .............................................................................. 140
7.5 JTAG interface ............................................................................................141
7.5.1 Multiple devices in the scan chain ..................................................... 141
7.5.2 Sample configuration dialog boxes .....................................................141
7.5.3 Determining values for scan chain configuration .................................. 142
7.5.4 JTAG Speed .................................................................................... 143
7.6 SWD interface ............................................................................................145
7.6.1 SWD speed .....................................................................................145
7.6.2 SWO .............................................................................................. 145
7.7 Multi-core debugging .................................................................................. 147
7.7.1 How multi-core debugging works .......................................................147
7.7.2 Using multi-core debugging in detail .................................................. 148
7.7.3 Things you should be aware of ......................................................... 149
7.8 Connecting multiple J-Links / J-Traces to your PC ........................................... 150
7.8.1 How does it work? .......................................................................... 150
7.9 J-Link control panel .................................................................................... 152
7.9.1 Tabs ...............................................................................................152
7.10 Reset strategies ........................................................................................158
7.11 Using DCC for memory access ................................................................... 159
7.11.1 What is required? .......................................................................... 159
7.11.2 Target DCC handler ........................................................................159
7.11.3 Target DCC abort handler ............................................................... 159
7.12 The J-Link settings file .............................................................................. 160
J-Link / J-Trace (UM08001)
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7.13
7.14
7.15
7.16
7.17
8
Flash download .........................................................................................................230
8.1
8.2
8.3
8.4
8.5
8.6
8.7
8.8
8.9
9
Introduction ............................................................................................... 231
Licensing ................................................................................................... 232
Supported devices ...................................................................................... 233
Setup for various debuggers (internal flash) .................................................. 234
Setup for various debuggers (CFI flash) ........................................................ 235
Setup for various debuggers (SPIFI flash) ..................................................... 236
QSPI flash support ..................................................................................... 237
8.7.1 Setup the DLL for QSPI flash download .............................................. 237
Using the DLL flash loaders in custom applications ......................................... 238
Debugging applications that change flash contents at runtime .......................... 239
Flash breakpoints ......................................................................................................240
9.1
9.2
9.3
9.4
9.5
9.6
10
7.12.1 SEGGER Embedded Studio ..............................................................160
7.12.2 Keil MDK-ARM (uVision) ................................................................. 160
7.12.3 IAR EWARM .................................................................................. 160
7.12.4 Mentor Sourcery CodeBench for ARM ............................................... 160
J-Link script files ...................................................................................... 161
7.13.1 Actions that can be customized ....................................................... 161
7.13.2 Script file API functions .................................................................. 168
7.13.3 Global DLL variables ...................................................................... 191
7.13.4 Global DLL constants ..................................................................... 195
7.13.5 Script file language ........................................................................ 197
7.13.6 Script file writing example .............................................................. 198
7.13.7 Executing J-Link script files .............................................................199
J-Link Command Strings ............................................................................200
7.14.1 List of available commands ............................................................. 200
7.14.2 Using J-Link Command Strings ........................................................ 225
Switching off CPU clock during debug ......................................................... 226
Cache handling .........................................................................................227
7.16.1 Cache coherency ........................................................................... 227
7.16.2 Cache clean area ........................................................................... 227
7.16.3 Cache handling of ARM7 cores ........................................................ 227
7.16.4 Cache handling of ARM9 cores ........................................................ 227
Virtual COM Port (VCOM) ...........................................................................228
7.17.1 Configuring Virtual COM Port ...........................................................228
Introduction ............................................................................................... 241
Licensing ................................................................................................... 242
9.2.1 Free for evaluation and non-commercial use ....................................... 242
Supported devices ...................................................................................... 243
Setup & compatibility with various debuggers ................................................ 244
9.4.1 Setup .............................................................................................244
9.4.2 Compatibility with various debuggers ................................................. 244
Flash Breakpoints in QSPI flash ....................................................................245
9.5.1 Setup .............................................................................................245
FAQ .......................................................................................................... 246
Monitor Mode Debugging ....................................................................................... 247
10.1
10.2
10.3
10.4
10.5
10.6
10.7
Introduction ............................................................................................. 248
Enable Monitor Debugging ......................................................................... 249
Availability and limitations of monitor mode ................................................. 250
10.3.1 Cortex-M3 .....................................................................................250
10.3.2 Cortex-M4 .....................................................................................250
Monitor code ............................................................................................ 251
Debugging interrupts ................................................................................ 252
Having servicing interrupts in debug mode .................................................. 253
Forwarding of Monitor Interrupts ................................................................ 254
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10.8
11
Low Power Debugging ............................................................................................256
11.1
11.2
11.3
12
Target application performs reset (Cortex-M) ............................................... 255
Introduction ............................................................................................. 257
Activating low power mode handling for J-Link ............................................. 258
Restrictions .............................................................................................. 259
Open Flashloader ................................................................................................... 260
12.1
12.2
12.3
12.4
12.5
Introduction ............................................................................................. 261
General procedure .................................................................................... 262
Adding a new device .................................................................................263
Editing/Extending an Existing Device ...........................................................264
XML Tags and Attributes ............................................................................265
12.5.1 ..................................................................................265
12.5.2 ..................................................................................... 265
12.5.3 ................................................................................... 265
12.5.4 ........................................................................... 267
12.6 Example XML file ...................................................................................... 269
12.7 Add. Info / Considerations / Limitations ....................................................... 270
12.7.1 CMSIS Flash Algorithms Compatibility .............................................. 270
12.7.2 Supported Cores ............................................................................270
12.7.3 Information for Silicon Vendors ....................................................... 270
12.7.4 Template Projects and How To's ...................................................... 270
13
J-Flash SPI ............................................................................................................. 271
13.1
Introduction ............................................................................................. 272
13.1.1 What is J-Flash SPI? ...................................................................... 272
13.1.2 J-Flash SPI CL (Windows, Linux, macOS) ..........................................273
13.1.3 Features ....................................................................................... 273
13.1.4 Requirements ................................................................................ 273
13.2 Licensing ................................................................................................. 274
13.2.1 Introduction .................................................................................. 274
13.3 Getting Started ........................................................................................ 275
13.3.1 Setup ........................................................................................... 275
13.3.2 Using J-Flash SPI for the first time .................................................. 275
13.3.3 Menu structure .............................................................................. 276
13.4 Settings ...................................................................................................279
13.4.1 Project Settings ............................................................................. 279
13.4.2 Global Settings ..............................................................................283
13.5 Command Line Interface ........................................................................... 285
13.5.1 Overview ...................................................................................... 285
13.5.2 Command line options ....................................................................285
13.5.3 Batch processing ........................................................................... 287
13.5.4 Programming multiple targets in parallel ...........................................287
13.6 Creating a new J-Flash SPI project ............................................................. 290
13.7 Custom Command Sequences .................................................................... 291
13.7.1 Init / Exit steps ............................................................................. 291
13.7.2 Example ....................................................................................... 291
13.7.3 J-Flash SPI Command Line Version .................................................. 292
13.8 Device specifics ........................................................................................ 295
13.8.1 SPI flashes with multiple erase commands ........................................ 295
13.9 Target systems .........................................................................................296
13.9.1 Which flash devices can be programmed? ......................................... 296
13.10 Performance ........................................................................................... 297
13.10.1 Performance values ...................................................................... 297
13.11 Background information ........................................................................... 298
13.11.1 SPI interface connection ............................................................... 298
13.12 Support ................................................................................................. 299
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13.12.1
13.12.2
14
RDI .......................................................................................................................... 300
14.1
14.2
14.3
14.4
14.5
15
Introduction ............................................................................................. 324
SWD multi-drop ....................................................................................... 325
15.2.1 How it works ................................................................................ 325
15.2.2 Setting up SWD multi-drop in the J-Link software .............................. 325
15.2.3 J-Link support ............................................................................... 325
RTT ......................................................................................................................... 326
16.1
16.2
16.3
16.4
16.5
16.6
16.7
17
Introduction ............................................................................................. 301
14.1.1 Features ....................................................................................... 301
Licensing ................................................................................................. 302
Setup for various debuggers ...................................................................... 303
14.3.1 ARM AXD (ARM Developer Suite, ADS) ............................................. 303
14.3.2 ARM RVDS (RealView developer suite) ..............................................305
14.3.3 GHS MULTI ................................................................................... 310
Configuration ........................................................................................... 313
14.4.1 Configuration file JLinkRDI.ini ..........................................................313
14.4.2 Using different configurations .......................................................... 313
14.4.3 Using multiple J-Links simultaneously ...............................................313
14.4.4 Configuration dialog ....................................................................... 313
Semihosting ............................................................................................. 322
14.5.1 Unexpected / unhandled SWIs .........................................................322
ARM SWD specifics ................................................................................................323
15.1
15.2
16
Troubleshooting ........................................................................... 299
Contacting support .......................................................................299
Introduction ............................................................................................. 327
How RTT works ........................................................................................ 328
16.2.1 Target implementation ....................................................................328
16.2.2 Locating the Control Block .............................................................. 328
16.2.3 Internal structures ......................................................................... 328
16.2.4 Requirements ................................................................................ 329
16.2.5 Performance ..................................................................................329
16.2.6 Memory footprint ........................................................................... 329
RTT Communication .................................................................................. 330
16.3.1 RTT Viewer ................................................................................... 330
16.3.2 RTT Client .....................................................................................330
16.3.3 RTT Logger ................................................................................... 330
16.3.4 RTT in other host applications ......................................................... 331
Implementation ........................................................................................ 332
16.4.1 API functions ................................................................................ 332
16.4.2 Configuration defines ..................................................................... 338
ARM Cortex - Background memory access ................................................... 341
Example code .......................................................................................... 342
FAQ ........................................................................................................ 343
Trace ....................................................................................................................... 344
17.1
Introduction ............................................................................................. 345
17.1.1 What is backtrace? ........................................................................ 345
17.1.2 What is streaming trace? ................................................................345
17.1.3 What is code coverage? ..................................................................345
17.1.4 What is code profiling? ................................................................... 346
17.2 Tracing via trace pins ................................................................................ 347
17.2.1 Cortex-M specifics ..........................................................................347
17.2.2 Trace signal timing ........................................................................ 347
17.2.3 Adjusting trace signal timing on J-Trace ............................................347
17.2.4 J-Trace models with support for streaming trace ................................ 348
J-Link / J-Trace (UM08001)
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17.3
Tracing with on-chip trace buffer ................................................................ 349
17.3.1 CPUs that provide tracing via pins and on-chip buffer ......................... 349
17.4 Target devices with trace support ............................................................... 350
17.5 Streaming trace ....................................................................................... 351
17.5.1 Download and execution address differ .............................................351
17.5.2 Do streaming trace without prior download ....................................... 351
18
Target interfaces and adapters ...............................................................................352
18.1
18.2
18.3
18.4
18.5
19
Background information .......................................................................................... 366
19.1
19.2
19.3
19.4
19.5
20
20-pin J-Link connector ............................................................................. 353
18.1.1 Pinout for JTAG ............................................................................. 353
18.1.2 Pinout for SWD ............................................................................. 355
18.1.3 Pinout for SWD + Virtual COM Port (VCOM) ...................................... 357
18.1.4 Pinout for SPI ............................................................................... 358
18.1.5 Pinout for QSPI ............................................................................. 359
19-pin JTAG/SWD and Trace connector ........................................................360
18.2.1 Connecting the target board ........................................................... 361
18.2.2 Target power supply ...................................................................... 361
9-pin JTAG/SWD connector ........................................................................ 363
Reference voltage (VTref) .......................................................................... 364
Adapters ..................................................................................................365
JTAG ....................................................................................................... 367
19.1.1 Test access port (TAP) ....................................................................367
19.1.2 Data registers ............................................................................... 367
19.1.3 Instruction register ........................................................................ 367
19.1.4 The TAP controller ......................................................................... 367
Embedded Trace Macrocell (ETM) ................................................................370
19.2.1 Trigger condition ............................................................................370
19.2.2 Code tracing and data tracing ......................................................... 370
19.2.3 J-Trace integration example - IAR Embedded Workbench for ARM ......... 370
Embedded Trace Buffer (ETB) .................................................................... 374
Flash programming ................................................................................... 375
19.4.1 How does flash programming via J-Link / J-Trace work? ...................... 375
19.4.2 Data download to RAM ................................................................... 375
19.4.3 Data download via DCC ..................................................................375
19.4.4 Available options for flash programming ........................................... 375
J-Link / J-Trace firmware ........................................................................... 377
19.5.1 Firmware update ........................................................................... 377
19.5.2 Invalidating the firmware ................................................................377
Designing the target board for trace .......................................................................379
20.1
Overview of high-speed board design ..........................................................380
20.1.1 Avoiding stubs ...............................................................................380
20.1.2 Minimizing Signal Skew (Balancing PCB Track Lengths) ....................... 380
20.1.3 Minimizing Crosstalk ...................................................................... 380
20.1.4 Using impedance matching and termination ...................................... 380
20.2 Terminating the trace signal .......................................................................381
20.2.1 Rules for series terminators ............................................................ 381
20.3 Signal requirements .................................................................................. 382
21
Semihosting .............................................................................................................383
21.1
Introduction ............................................................................................. 384
21.1.1 Advantages ................................................................................... 384
21.1.2 Disadvantages ............................................................................... 384
21.2 Debugger support .....................................................................................385
21.3 Implementation ........................................................................................ 386
21.3.1 SVC instruction ............................................................................. 386
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21.3.2 Breakpoint instruction .................................................................... 386
21.3.3 J-Link GDBServer optimized version ................................................. 386
21.4 Communication protocol ............................................................................ 389
21.4.1 Register R0 ...................................................................................389
21.4.2 Command SYS_OPEN (0x01) .......................................................... 389
21.4.3 Command SYS_CLOSE (0x02) ......................................................... 390
21.4.4 Command SYS_WRITEC (0x03) ....................................................... 390
21.4.5 Command SYS_WRITE0 (0x04) ....................................................... 391
21.4.6 Command SYS_WRITE (0x05) ......................................................... 391
21.4.7 Command SYS_READ (0x06) .......................................................... 391
21.4.8 Command SYS_READC (0x07) .........................................................392
21.4.9 Command SYS_ISTTY (0x09) .......................................................... 392
21.4.10 Command SYS_SEEK (0x0A) ......................................................... 392
21.4.11 Command SYS_FLEN (0x0C) ......................................................... 393
21.4.12 Command SYS_REMOVE (0x0E) .....................................................393
21.4.13 Command SYS_RENAME (0x0F) ..................................................... 393
21.4.14 Command SYS_GET_CMDLINE (0x15) ............................................ 394
21.4.15 Command SYS_EXIT (0x18) .......................................................... 394
21.5 Enabling semihosting in J-Link GDBServer ................................................... 395
21.5.1 SVC variant .................................................................................. 395
21.5.2 Breakpoint variant ......................................................................... 395
21.5.3 J-Link GDBServer optimized variant ................................................. 395
21.6 Enabling Semihosting in J-Link RDI + AXD .................................................. 396
21.6.1 Using SWIs in your application ........................................................ 396
22
Environmental Conditions & Safety ........................................................................ 397
22.1
J-Link ...................................................................................................... 398
22.1.1 Affected models .............................................................................398
22.2 Flasher .................................................................................................... 399
22.2.1 Affected models .............................................................................399
22.3 J-Trace .................................................................................................... 400
22.3.1 Affected models .............................................................................400
23
Support and FAQs .................................................................................................. 401
23.1
23.2
Measuring download speed ........................................................................ 402
Troubleshooting ........................................................................................ 403
23.2.1 General procedure ......................................................................... 403
23.3 Contacting support ................................................................................... 404
23.3.1 Contact Information ....................................................................... 404
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
Chapter 1
Introduction
This is the user documentation for owners of SEGGER debug probes, J-Link and J-Trace.
This manual documents the software which with the J-Link Software and Documentation
Package as well as advanced features of J-Link and J-Trace, like Real Time Transfer (RTT),
J-Link Script Files or Trace.
J-Link / J-Trace (UM08001)
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1.1
CHAPTER 1
Requirements
Requirements
Host System
To use J-Link or J-Trace you need a host system running Windows 2000 or later. For a list
of all operating systems which are supported by J-Link, please refer to Supported OS on
page 30.
Target System
A target system with a supported CPU is required. You should make sure that the emulator
you are looking at supports your target CPU. For more information about which J-Link features are supported by each emulator, please refer to SEGGER debug probes on page 35.
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CHAPTER 1
1.2
Supported OS
Supported OS
J-Link/J-Trace can be used on the following operating systems:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Microsoft Windows 2000
Microsoft Windows XP
Microsoft Windows XP x64
Microsoft Windows 2003
Microsoft Windows 2003 x64
Microsoft Windows Vista
Microsoft Windows Vista x64
Microsoft Windows 7
Microsoft Windows 7 x64
Microsoft Windows 8
Microsoft Windows 8 x64
Microsoft Windows 10
Microsoft Windows 10 x64
Linux
macOS 10.5 and higher
J-Link / J-Trace (UM08001)
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CHAPTER 1
1.3
Common features of the J-Link product family
Common features of the J-Link product family
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
USB 2.0 interface (Full-Speed/Hi-Speed, depends on J-Link model)
Any ARM7/ARM9/ARM11 (including thumb mode), Cortex-A5/A7/A8/A9/A12/A15/A17,
Cortex-M0/M1/M3/M4/M7/M23/M33, Cortex-R4/R5 core supported
Automatic core recognition
Maximum interface speed 15/50 MHz (depends on J-Link model)
Seamless integration into all major IDEs ( List of supported IDEs )
No power supply required, powered through USB
Support for adaptive clocking
All JTAG signals can be monitored, target voltage can be measured
Support for multiple devices
Fully plug and play compatible
Standard 20-pin JTAG/SWD connector, 19-pin JTAG/SWD and Trace connector, standard
38-pin JTAG+Trace connector
USB and 20-pin ribbon cable included
Memory viewer (J-Mem) included
Remote server included, which allows using J-Trace via TCP/IP networks
RDI interface available, which allows using J-Link with RDI compliant software
Flash programming software (J-Flash) available
Flash DLL available, which allows using flash functionality in custom applications
Software Developer Kit (SDK) available
14-pin JTAG adapter available
J-Link 19-pin Cortex-M Adapter available
J-Link 9-pin Cortex-M Adapter available
Adapter for 5V JTAG targets available for hardware revisions up to 5.3
Optical isolation adapter for JTAG/SWD interface available
Target power supply via pin 19 of the JTAG/SWD interface (up to 300 mA to target
with overload protection), alternatively on pins 11 and 13 of the Cortex-M 19-pin trace
connector
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1.4
CHAPTER 1
Supported CPU cores
Supported CPU cores
J-Link / J-Trace supports any common ARM Cortex core, ARM legacy core, Microchip PIC32
core and Renesas RX core. For a detailed list, please refer to:
SEGGER website: Supported Cores .
If you experience problems with a particular core, do not hesitate to contact SEGGER.
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1.5
Built-in intelligence for supported CPU-cores
Built-in intelligence for supported CPU-cores
In general, there are two ways to support a CPU-core in the J-Link software:
1. Intelligence in the J-Link firmware
2. Intelligence on the PC-side (DLL)
Having the intelligence in the firmware is ideal since it is much more powerful and robust.
The J-Link PC software automatically detects which implementation level is supported for
the connected CPU-core. If intelligence in the firmware is available, it is used. If you are
using a J-Link that does not have intelligence in the firmware and only PC-side intelligence
is available for the connected CPU, a warning message is shown.
1.5.1
Intelligence in the J-Link firmware
On newer J-Links, the intelligence for a new CPU-core is also available in the J-Link firmware
which means that for these J-Links, the target sequences are no longer generated on the PCside but directly inside the J-Link. Having the intelligence in the firmware leads to improved
stability and higher performance.
1.5.2
Intelligence on the PC-side (DLL)
This is the basic implementation level for support of a CPU-core. This implementation is
not J-Link model dependent, since no intelligence for the CPU-core is necessary in the JLink firmware. This means, all target sequences (JTAG/SWD/…) are generated on the PCside and the J-Link simply sends out these sequences and sends the result back to the DLL.
Using this way of implementation also allows old J-Links to be used with new CPU cores as
long as a DLL-Version is used which has intelligence for the CPU.
But there is one big disadvantage of implementing the CPU core support on the DLL-side:
For every sequence which shall be sent to the target a USB or Ethernet transaction is
triggered. The long latency especially on a USB connection significantly affects the performance of J-Link. This is true especially when performing actions where J-Link has to wait
for the CPU frequently. An example is a memory read/write operation which needs to be
followed by status read operations or repeated until the memory operation is completed.
Performing this kind of task with only PC-side intelligence requires to either make some
assumption like: Operation is completed after a given number of cycles. Or it requires to
make a lot of USB/Ethernet transactions. The first option (fast mode) will not work under
some circumstances such as low CPU speeds, the second (slow mode) will be more reliable
but very slow due to the high number of USB/Ethernet transactions. It simply boils down
to: The best solution is having intelligence in the emulator itself!
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1.5.2.1
•
•
•
Built-in intelligence for supported CPU-cores
Limitations of PC-side implementations
Instability, especially on slow targets
Due to the fact that a lot of USB transactions would cause a very bad performance of JLink, PC-side implementations are on the assumption that the CPU/Debug interface is
fast enough to handle the commands/requests without the need of waiting. So, when
using the PC-side-intelligence, stability cannot be guaranteed in all cases, especially if
the target interface speed (JTAG/SWD/…) is significantly higher than the CPU speed.
Poor performance
Since a lot more data has to be transferred over the host interface (typically USB),
the resulting download speed is typically much lower than for implementations with
intelligence in the firmware, even if the number of transactions over the host interface
is limited to a minimum (fast mode).
No support
Please understand that we cannot give any support if you are running into problems
when using a PC-side implementation.
Note
Due to these limitations, we recommend to use PC-side implementations for evaluation
only.
1.5.3
Firmware intelligence per model
There are different models of J-Link / J-Trace which have built-in intelligence for different
CPU-cores. Please refer to J-Link / J-Trace hardware revisions for further information.
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1.6
Where to find further information
Where to find further information
The following items are not the scope of the J-Link / J-Trace User Guide (UM08001) and
therefore documented elsewhere in the respective place described/listed below.
1.6.1
1.6.1.1
SEGGER debug probes
J-Link / J-Trace current model overview
In order to compare features, performance specifications, capabilities and included licenses
of current J-Link / J-Trace or Flasher models, please refer to the SEGGER website:
J-Link Model overview
1.6.1.2
J-Link / J-Trace hardware revisions
For feature comparisons between different hardware revisions of J-Link / J-Trace or Flasher
models, please refer to:
SEGGER Wiki: J-Link / J-Trace / Flasher Software and Hardware features overview
1.6.1.3
J-Link / J-Trace hardware specifications
For detailed general, mechanical and electrical specifications of a specific J-Link / J-Trace
or Flasher model, please refer to:
SEGGER Wiki: J-Link / J-Trace / Flasher general, mechanical, electrical specifications
1.6.2
Using a feature in a specific development environment
For many features described in this manual, detailed explanations on how to use them
with popular debuggers, IDEs and other applications are available in the SEGGER wiki.
Therefore, for information on how to use a feature in a specific development environment,
please refer to:
SEGGER Wiki: Getting Started with Various IDEs .
If an explanation is missing for the IDE used or the IDE used is not listed at all, please
contact us. (see Contact Information )
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
Chapter 2
Licensing
This chapter describes the different license types of J-Link related software and the legal
use of the J-Link software with original SEGGER and OEM products.
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2.1
CHAPTER 2
Components requiring a license
Components requiring a license
J-Link PLUS and higher are fully featured J-Links and come with all licenses included. Other
models may do not come with all features enabled. For a detailed overview of the included
licenses of the SEGGER debug probes, please refer to:
J-Link Model overview: Licenses
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2.2
Legal use of SEGGER J-Link software
Legal use of SEGGER J-Link software
The software consists of proprietary programs of SEGGER, protected under copyright and
trade secret laws. All rights, title and interest in the software are and shall remain with
SEGGER. For details, please refer to the license agreement which needs to be accepted
when installing the software. The text of the license agreement is also available as entry
in the start menu after installing the software.
Use of software
SEGGER J-Link software may only be used with original SEGGER products and authorized
OEM products. The use of the licensed software to operate SEGGER product clones is prohibited and illegal.
2.2.1
Use of the software with 3rd party tools
For simplicity, some components of the J-Link software are also distributed by partners
with software tools designed to use J-Link. These tools are primarily debugging tools, but
also memory viewers, flash programming utilities as well as software for other purposes.
Distribution of the software components is legal for our partners, but the same rules as
described above apply for their usage: They may only be used with original SEGGER products and authorized OEM products. The use of the licensed software to operate SEGGER
product clones is prohibited and illegal.
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2.3
CHAPTER 2
Illegal Clones
Illegal Clones
Clones are copies of SEGGER products which use the copyrighted SEGGER Firmware without a license. It is strictly prohibited to use SEGGER J-Link software with illegal clones of
SEGGER products. Manufacturing and selling these clones is an illegal act for various reasons, amongst them trademark, copyright and unfair business practice issues. The use of
illegal J-Link clones with this software is a violation of US, European and other international
laws and is prohibited. If you are in doubt if your unit may be legally used with SEGGER
J-Link software, please get in touch with us. End users may be liable for illegal use of JLink software with clones.
J-Link / J-Trace (UM08001)
© 2004-2021 SEGGER Microcontroller GmbH
Chapter 3
J-Link software and
documentation package
This chapter describes the contents of the J-Link Software and Documentation Package
which can be downloaded from www.segger.com .
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3.1
Software overview
Software overview
The J-Link Software and Documentation Package, which is available for download from
segger.com/downloads/jlink , includes some applications to be used with J-Link. It also
comes with USB-drivers for J-Link and documentations in pdf format.
Software
Description
J-Link Commander
Command-line tool with basic functionality for target analysis.
J-Link GDB Server
The J-Link GDB Server is a server connecting to the GNU Debugger (GDB) via TCP/IP. It is required for toolchains using the
GDB protocol to connect to J-Link.
J-Link GDB Server
command line version
Command line version of the J-Link GDB Server. Same functionality as the GUI version.
J-Link Remote Server
Utility which provides the possibility to use J-Link / J-Trace remotely via TCP/IP.
J-Mem
Target memory viewer. Shows the memory content of a running target and allows editing as well.
J-Flasha
Stand-alone flash programming application. For more information about J-Flash please refer to J-Flash ARM User’s Guide
(UM08003).
J-Flash Lite
Stand-alone flash programming application. Reduced feature
set of J-Flash
J-Link RTT Viewer
Free-of-charge utility for J-Link. Displays the terminal output
of the target using RTT. Can be used in parallel with a debugger or stand-alone.
J-Link SWO Viewer
Free-of-charge utility for J-Link. Displays the terminal output
of the target using the SWO pin. Can be used in parallel with a
debugger or stand-alone.
J-Link SWO Analyzer
Command line tool that analyzes SWO RAW output and stores
it into a file.
JTAGLoad
Command line tool that opens an svf file and sends the data in
it via J-Link / J-Trace to the target.
J-Link Configurator
GUI-based configuration tool for J-Link. Allows configuration of
USB identification as well as TCP/IP identification of J-Link. For
more information about the J-Link Configurator, please refer
to J-Link Configurator .
RDI supporta
Provides Remote Debug Interface (RDI) support. This allows
the user to use J-Link with any RDI-compliant debugger.
Processor specific tools
Free command-line tools for handling specific processors.
Included are: STR9 Commander and STM32 Unlock.
a
Full-featured J-Link (PLUS, PRO, ULTRA+) or an additional license for J-Link base model
required.
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3.2
J-Link Commander (Command line tool)
J-Link Commander (Command line tool)
For more information on the commands supported by the J-Link Commander, please refer
to the SEGGER wiki:
SEGGER Wiki: J-Link commander
3.2.1
Command line options
For more information on the command line options supported by the J-Link Commander,
please refer to the SEGGER wiki:
SEGGER Wiki: J-Link commander
3.2.2
Using J-Link Command Files
For more information on how to use J-Link Command Files with J-Link Commander, please
refer to the SEGGER wiki:
SEGGER Wiki: J-Link commander
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3.3
J-Link Remote Server
J-Link Remote Server
J-Link Remote Server allows using J-Link / J-Trace remotely via TCP/IP. This enables you
to connect to and fully use a J-Link / J-Trace from another computer. Performance is just
slightly (about 10%) lower than with direct USB connection.
J-Link Remote Server
3.3.1
List of available commands
The table below lists the commands line options accepted by the J-Link Remote Server
Command
Description
?
Prints the list of available command line options.
-Port
Specifies listening port of J-Link Remote Server.
-UseTunnel
Specifies if tunneled connection shall be used.
-SelectEmuBySN
Specifies to connect to a J-Link with a specific S/N. Only
valid for LAN mode.
-TunnelServer
Specify a tunnel server to connect to (default: jlink.segger.com:19020). Only valid for tunnel mode.
-TunnelBySN
Specifies to identify at tunnel server via J-Link S/N. Only
valid for tunnel mode.
-TunnelByName
Specifies to identify at tunnel server via custom name. Only
valid for tunnel mode.
-TunnelPW
Specifies to protect the connection with a password. Only
valid for tunnel mode.
-TunnelPort
Specifies to connect to a tunnel server listening on a specific
port. Only valid for tunnel mode.
-TunnelEncrypt
Specifies to encrypt any transferred data of a tunneled connection
-select
[=] Specify how to connect to JLink.
port 1
Selects the IP port on which the J-Link Remote Server is listening.
UseTunnel 1
Starts J-Link Remote Server in tunneling mode
SelectEmuBySN 1
Selects the J-Link to connect to by its serial number.
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J-Link Remote Server
Note
1:
These command line options exist because of backwards-compatibility.
We suggest to use the command line options that start with a dash (’-’).
3.3.2
Tunneling mode
The Remote server provides a tunneling mode which allows remote connection to a J-Link /
J-Trace from any computer, even from outside the local network.
To give access to a J-Link neither a remote desktop or VPN connection nor changing some
difficult firewall settings is necessary.
When started in tunneling mode the Remote server connects to the SEGGER tunnel server
via port 19020 and registers with its serial number. To connect to the J-Link from the
remote computer an also simple connection to tunnel: can be established and
the debugger is connected to the J-Link.
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J-Link Remote Server
J-Link Remote Server: Connected to SEGGER tunnel server
Example scenario
A device vendor is developing a new device which shall be supported by J-Link. Because
there is only one prototype, a shipment to SEGGER is not possible.
Instead the vendor can connect the device via J-Link to a local computer and start the
Remote server in tunneling mode. The serial number of the J-Link is then sent to a to an
engineer at SEGGER.
The engineer at SEGGER can use J-Link Commander or a debugger to test and debug the
new device without the need to have the device on the desk.
Start J-Link Remote Server in tunneling mode
3.3.3 Connecting to J-Link/ J-Trace using J-Link Remote
Server
J-Link Commander can be used to connect to the J-Link over the Remote Server:
1.) Start J-Link Commander
2.) From within J-Link Commander enter:
IP for a Remote Server running in LAN mode.
IP tunnel:[:[:tunnelserver[:port]]] for a Remote Server
running in tunneling mode.
3.) If the connection was successful it should look like in this screenshot:
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J-Link Remote Server
Troubleshooting
Problem
Solution
Remote server cannot connect to tunnel server.
1. Make sure the Remote server is not blocked by any firewall.
2. Make sure port 19020 is not blocked by any firewall.
3. Contact network admin.
J-Link Commander
cannot connect to
tunnel server.
1. Make sure Remote server is started correctly.
2. Make sure the entered serial number is correct.
3. Make sure port 19020 is not blocked by any firewall. Contact
network admin.
To test whether a connection to the tunnel server can be established or not a network
protocol analyzer like Wireshark can help. The network transfer of a successful connection
should look like:
3.3.3.1
Examples
IP 192.168.178.14 Connect over a Remote Server in your local network (You need to
know the specific local IP).
IP tunnel:ThisIsAName Connect over the default Tunnel Remote Server (The one from
SEGGER) by using the Name you assigned to the J-Link.
IP tunnel:174402383 Connect over the default Tunnel Remote Server by using the Serial
Number of the J-Link.
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3.3.4
J-Link Remote Server
Encrypted connection
The J-Link Remote Server V6.53b and later supports encrypted connections in tunnel
mode.
That means that it is possible to have a remote J-Link session where any data transferred
between Client, Tunnel Server and Remote Server is encrypted. The encryption is done by
using end-to-end encryption between the J-Link Remote Server and a client application,
powered by SEGGER’s emCrypt.
For more information on emCrypt, please refer to emCrypt on segger.com .
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3.4
CHAPTER 3
J-Mem Memory Viewer
J-Mem Memory Viewer
J-Mem is a GUI application to display and modify the RAM and SFRs (Special Function
Registers) of target systems while the target is running.
For more information on how to use J-Mem, please refer to J-Mem on page 117
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3.5
CHAPTER 3
J-Flash
J-Flash
J-Flash is an application to program data images to the flash of a target device. With JFlash the internal flash of all J-Link supported devices can be programmed, as well as
common external flashes connected to the device. Beside flash programming all other flash
operations like erase, blank check and flash content verification can be done.
J-Flash requires an additional license from SEGGER to enable programming. For license
keys, as well as evaluation licenses got to www.segger.com or contact us directly.
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3.6
J-Flash Lite
J-Flash Lite
J-Flash Lite is a flash programming application to program data images to the flash of a
target device. In comparison to J-Flash, J-Flash Lite has a reduced feature set but does not
require a J-Link PLUS or higher to operate. J-Flash Lite is also available for J-Link BASE
and EDU.
3.6.1
•
•
•
•
3.6.2
Limitations in comparison to J-Flash
No support for external CFI NOR flash
No support for custom Init steps
No support for automation via command line
No project management support (Only the settings from the last session are preselected on startup)
Usage
J-Flash Lite is very simple to use. First, a configuration dialog shows up, in which the target
interface, target device etc. has to be selected. By clicking the O.K. button, the configuration
is applied and the actual main window is shown.
The main window of J-Flash Lite only consists of a few dialog elements that allow programming of the target:
Dialog element
Function
“…” button
Selects the application image (bin, hex, mot, …) to program
“Erase chip”
button
Erases all flash banks of the device
“Program Device” button
Programs the selected application image
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J-Flash Lite
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3.7
J-Link RTT Viewer
J-Link RTT Viewer
J-Link RTT Viewer is a GUI application available for Windows, MacOS and Linux.
It enables you to use all features of RTT in one application.
It supports:
•
•
•
•
•
•
Displaying terminal output of Channel 0.
Up to 16 virtual Terminals on Channel 0.
Sending text input to Channel 0.
Interpreting text control codes for colored text and controlling the Terminal.
Logging terminal data into a file.
Logging data on Channel 1.
For general information about RTT, please refer to RTT on page 326.
3.7.1
RTT Viewer Startup
Make sure J-Link and target device are connected and powered up.
Start RTT Viewer by opening the executable (JLinkRTTViewer.exe) from the installation
folder of the J-Link Software or the start menu. Unless the command line parameter -autoconnect is set, the Configuration Dialog will pop up.
Configure the Connection Settings as described below and click OK. The connection settings
and all in app configuration will be saved for the next start of J-Link RTT Viewer.
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3.7.2
J-Link RTT Viewer
Connection Settings
RTT Viewer can be used in two modes:
•
•
Stand-alone, opening an own connection to J-Link and target.
In attach mode, connecting to an existing J-Link connection of a debugger.
Stand-alone connection settings
In stand-alone mode RTT Viewer needs to know some settings of J-Link and target device.
Select USB or TCP/IP as the connection to J-Link. For USB a specific J-Link serial number
can optionally be entered, for TCP/IP the IP or hostname of the J-Link has to be entered.
Select the target device to connect to. This allows J-Link to search in the known RAM of
the target.
Select the target interface and its speed. The RTT Control Block can be searched for fully
automatically, it can be set to a fixed address or it can be searched for in one or more
specific memory ranges.
Attaching to a connection
In attach mode RTT Viewer does not need any settings. Select Existing Session. For attach
mode a connection to J-Link has to be opened and configured by another application like a
debugger or simply J-Link Commander. If the RTT Control Block cannot be found automatically, configuration of its location has to be done by the debugger / application.
3.7.3
The Terminal Tabs
RTT Viewer allows displaying the output of Channel 0 in different “virtual” Terminals. The
target application can switch between terminals with SEGGER_RTT_SetTerminal() and SEGGER_RTT_TerminalOut(). RTT Viewer displays the Terminals in different tabs.
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J-Link RTT Viewer
All Terminals
The All Terminals tab displays the complete output of RTT Channel 0 and can display the
user input (Check Input -> Echo input… -> Echo to “All Terminals”).
Each output line is prefixed by the Terminal it has been sent to. Additionally, output on
Terminal 1 is shown in red, output on Terminals 2 - 15 in gray.
Terminal 0 - 15
Each tab Terminal 0 - Terminal 15 displays the output which has been sent to this Terminal.
The Terminal tabs interpret and display Text Control Codes as sent by the application to
show colored text or erase the screen.
By default, if the RTT application does not set a Terminal Id, the output is displayed in
Terminal 0.
The Terminal 0 tab can additionally display the user input. (Check Input -> Echo input…
-> Echo to “Terminal 0”)
Each Terminal tab can be shown or hidden via the menu Terminals -> Terminals… or their
respective shortcuts as described below.
3.7.4
Sending Input
RTT Viewer supports sending user input to RTT Down Channel 0 which can be read by the
target application with SEGGER_RTT_GetKey() and SEGGER_RTT_Read().
Input can be entered in the text box below the Terminal Tabs.
RTT Viewer can be configured to directly send each character while typing or buffer it until
Enter is pressed (Menu Input -> Sending…).
In stand-alone mode RTT Viewer can retry to send input, in case the target input buffer is
full, until all data could be sent to the target via Input -> Sending… -> Block if FIFO full.
3.7.5
Logging Terminal output
The output of Channel 0 can be logged into a text file. The format is the same as used in the
All Terminals tab. Terminal Logging can be started via Logging -> Start Terminal Logging…
3.7.6
Logging Data
Additionally to displaying output of Channel 0, RTT Viewer can log data which is sent on
RTT Channel 1 into a file. This can for example be used to sent instrumented event tracing
data. The data log file contains header and footer and the binary data as received from
the application.
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J-Link RTT Viewer
Data Logging can be started via Logging -> Start Data Logging…
Note
Data Logging is only available in stand-alone mode.
3.7.7
Command line options
J-Link RTT Viewer can be configured via command line parameters. In the following, the
command line options which are available for J-Link RTT Viewer are explained. All command
line options are case insensitive. Short and long command names have the same syntax.
Command line option
Explanation
-b, --bright
Bright theme for GUI
-d, --device
Select the connected target device.
-ct, --connection
Sets the connection type
-if, --interface
Sets the interface type
-ip, --host
The IP address of the J-Link
-s, --speed
Interface speed in kHz
-sf, --scriptfile
Executes a command script on start up
-sn, --serialnumber
Select the J-Link with a specific S/N.
-ra, --rttaddr
Sets the address of the RTT control block
-rr, --rttrange
Specify RTT search range
-a, --autoconnect
Automatically connect to target, suppress settings dialog
3.7.7.1
--bright
Starts the RTT Viewer in bright theme
Syntax
--bright
Example
JLinkRTTViewer.exe --bright
3.7.7.2
--device
Selects the device J-Link RTT Viewer shall connect to.
Syntax
--device
Example
JLinkRTTViewer.exe --device STM32F103ZE
3.7.7.3
--connection
Sets the connection type. The connection to the J-Link can either be made directly over
USB, IP or using an existing running session (e.g. the IDE’s debug session). In case of using
an existing session, no further configuration options are required.
Syntax
--connection
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J-Link RTT Viewer
Example
JLinkRTTViewer.exe --connection ip
3.7.7.4
--interface
Sets the interface J-Link shall use to connect to the target. As interface types FINE, JTAG
and SWD are supported.
Syntax
--interface
Example
JLinkRTTViewer.exe --interface swd
3.7.7.5
--host
Enter the IP address or hostname of the J-Link. This option only applies, if connection type
IP is used. Use * as for a list of available J-Links in the local subnet.
Syntax
--host
Example
JLinkRTTViewer.exe --host 192.168.1.17
3.7.7.6
--speed
Sets the interface speed in kHz for target communication.
Syntax
--speed
Example
JLinkRTTViewer.exe --speed 4000
3.7.7.7
--scriptfile
Executes a JLink command script on startup, setting options in advance (e.g. Device =
AT91SAM7S256)
Syntax
--scriptfile
Example
JLinkRTTViewer.exe --scriptfile C:\tmp\
3.7.7.8
--serialnumber
Connect to a J-Link with a specific serial number via USB. Useful if multiple J-Links are
connected to the same PC and multiple instances of J-Link RTT Viewer shall run and each
connects to another J-Link.
Syntax
--serialnumber
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J-Link RTT Viewer
Example
JLinkRTTViewer.exe --serialnumber 580011111
3.7.7.9
--rttaddr
Sets a fixed address as location of the RTT control block. Automatic searching for the RTT
control block is disabled.
Syntax
--rttaddr
Example
JLinkRTTViewer.exe -rttaddr 0x20000000
3.7.7.10
--rttrange
Sets one or more memory ranges, where the J-Link DLL shall search for the RTT control
block.
Syntax
--rttrange
]>
[,
Example
JLinkRTTViewer.exe -rttrange “20000000 400”
3.7.7.11
--autoconnect
Let J-Link RTT Viewer connect automatically to the target without showing the Connection
Settings (see Connection Settings ).
Syntax
--autoconnect
Example
JLinkRTTViewer.exe --autoconnect
3.7.8
Menus and Shortcuts
File menu elements
Menu entry
Contents
Shortcut
-> Connect…
Opens the connect dialog and connects to the targets
F2
-> Disconnect
Disconnects from the target
F3
-> Exit
Closes connection and exit RTT Viewer.
Alt-F4
Terminals menu elements
Menu entry
Contents
Shortcut
-> Add next terminal
Opens the next available Terminal Tab.
Alt-A
-> Clear active terminal
Clears the currently selected terminal tab.
Alt-R
-> Close active terminal
Closes the active Terminal Tab.
Alt-W
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Menu entry
J-Link RTT Viewer
Contents
Shortcut
-> Open Terminal on
output
If selected, a terminal is automatically created, if
data for this terminal is received.
-> Show Log
Opens or closes the Log Tab.
Alt-L
Opens or closes the Terminal Tab.
AltShift-0
AltShift-F
Terminals -> Terminals…
-> Terminal 0 - 15
Input menu elements
Menu entry
-> Clear input field
Contents
Clears the input field without sending entered data.
Shortcut
Button
“Clear”
Input -> Sending…
-> Send on Input
If selected, entered input will be sent directly to
the target while typing.
-> Send on Enter
If selected, entered input will be sent when pressing Enter.
-> Block if FIFO full
If checked, RTT Viewer will retry to send all input
to the target when the target buffer is full.
Input -> End of line…
-> Windows format (CR
+LF)
-> Unix format (LF)
-> Mac format (CR)
-> None
Selects the end of line character to be sent on Enter.
Input -> Echo input…
-> Echo to “All Terminals”
If checked, sent input will be displayed in the All
Terminals Tab.
-> Echo to “Terminal 0”
If checked, sent input will be displayed in the Terminal Tab 0.
Logging menu elements
Menu entry
-> Start Terminal logging…
Contents
Starts logging terminal data to a file.
Shortcut
F5
-> Stop Terminal logging Stops logging terminal data and closes the file.
Shift-F5
-> Start Data logging…
Starts logging data of Channel 1 to a file.
F6
-> Stop Data logging
Stops logging data and closes the file.
Shift-F6
-> Channel infos…
Displays information about all available RTT channels.
F8
Help menu elements
Menu entry
Contents
Shortcut
-> About…
Shows version info of RTT Viewer.
F12
-> J-Link Manual…
Opens the J-Link Manual PDF file.
F11
-> RTT Webpage…
Opens the RTT webpage.
F10
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Tab context menu elements
Menu entry
Contents
Shortcut
-> Close Terminal
Closes this Terminal Tab
Alt-W
-> Clear Terminal
Clears the displayed output of this Terminal Tab.
Alt-R
3.7.9
Using "virtual" Terminals in RTT
For virtual Terminals the target application needs only Up Channel 0. This is especially
important on targets with low RAM.
If nothing is configured, all data is sent to Terminal 0.
The Terminal to output all following via Write, WriteString or printf can be set with SEGGER_RTT_SetTerminal().
Output of only one string via a specific Terminal can be done with SEGGER_RTT_TerminalOut().
The sequences sent to change the Terminal are interpreted by RTT Viewer. Other applications like a Telnet Client will ignore them.
3.7.10
Using Text Control Codes
RTT allows using Text Control Codes (ANSI escape codes) to configure the display of text.
RTT Viewer supports changing the text color and background color and can erase the Terminal. These Control Codes are pre-defined in the RTT application and can easily be used
in the application.
Example 1
SEGGER_RTT_WriteString(0,
RTT_CTRL_RESET"Red: " \
RTT_CTRL_TEXT_BRIGHT_RED"This text is red. " \
RTT_CTRL_TEXT_BLACK"" \
RTT_CTRL_BG_BRIGHT_RED"This background is red. " \
RTT_CTRL_RESET"Normal text again."
);
Example 2
SEGGER_RTT_printf(0, "%sTime:%s%s %.7d\n",
RTT_CTRL_RESET,
RTT_CTRL_BG_BRIGHT_RED,
RTT_CTRL_TEXT_BRIGHT_WHITE,
1111111
);
//
// Clear the terminal.
// The first line will not be shown after this command.
//
SEGGER_RTT_WriteString(0, RTT_CTRL_CLEAR);
SEGGER_RTT_printf(0, "%sTime: %s%s%.7d\n",
RTT_CTRL_RESET,
RTT_CTRL_BG_BRIGHT_RED,
RTT_CTRL_TEXT_BRIGHT_WHITE,
2222222
);
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3.8
J-Link SWO Viewer
J-Link SWO Viewer
Free-of-charge utility for J-Link. Displays the terminal output of the target using the SWO
pin. The stimulus port(s) from which SWO data is received can be chosen by using the
port checkboxes 0 to 31. Can be used in parallel with a debugger or stand-alone. This is
especially useful when using debuggers which do not come with built-in support for SWO
such as most GDB / GDB+Eclipse based debug environments.
3.8.1
J-Link SWO Viewer CL
Command line-only version of SWO Viewer. All commands available for J-Link SWO Viewer
can be used with J-Link SWO Viewer Cl. Similar to the GUI Version, J-Link SWO Viewer CL
asks for a device name or CPU clock speed at startup to be able to calculate the correct
SWO speed or to connect to a running J-Link GDB Server.
Using the syntax given below(see List of available command line options ), J-Link SWO
Viewer CL can be directly started with parameters.
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3.8.2
J-Link SWO Viewer
Usage
J-Link SWO Viewer is available via the start menu. It asks for a device name or CPU clock
speed at startup to be able to calculate the correct SWO speed or to connect to a running
J-Link GDB Server.
Optionally you can select the preferred SWO clock speed from a drop down list. If nothing
is selected for SWO clock speed then the debug probe will calculate the optimal value. To
populate the drop down list the device needs to be selected or CPU clock speed must be
measured once per session.
When running in normal mode J-Link SWO Viewer automatically performs the necessary
initialization to enable SWO output on the target, in GDB Server mode the initialization
has to be done by the debugger. Should you have a target connection already open e.g. a
debug session in your IDE we recommend defining the parameters device name, CPU clock
frequency and SWO clock frequency via CL to avoid connection errors.
3.8.3
List of available command line options
J-Link SWO Viewer can also be controlled from the command line if used in a automated
test environment etc. When passing all necessary information to the utility via command
line, the configuration dialog at startup is suppressed. Minimum information needed by JLink SWO Viewer is the device name (to enable CPU frequency auto detection) or the CPU
clock speed. The table below lists the commands accepted by the J-Link SWO View
Command
Description
-cpufreq
Select the CPU frequency.
-device
Select the target device.
-ip
Configure connection settings to IP IPAddress.
-itmmask
Selects a set of itm stimulus ports which should be used to
listen to.
-itmport
Selects a itm stimulus port which should be used to listen to.
-outputfile
Print the output of SWO Viewer to the selected file.
-settingsfile
Specify a J-Link settings file.
-swofreq
Select the SWO frequency.
-usb
Configure connection settings to USB S/N.
3.8.3.1
-cpufreq
Defines the current CPU speed in Hz that the CPU is running at. If the CPU is for example
running at 96 MHz, the command line should look as below.
Syntax
-cpufreq
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Example
-cpufreq 96000000
3.8.3.2
-device
Select the target device to enable the CPU frequency auto detection of the J-Link DLL. To
select a ST STM32F207IG as target device, the command line should look as below. For a
list of all supported device names, please refer to:
List of supported target devices
Syntax
-device
Example
-device STM32F207IG
3.8.3.3
-ip
Selects IP as host interface to connect to J-Link. Default host interface is USB.
Syntax
-ip
Example
-ip 192.168.1.17
3.8.3.4
-itmmask
Defines a set of stimulusports from which SWO data is received and displayed by SWO
Viewer. If itmmask is given, itmport will be ignored.
Syntax
-itmmask
Example
Listen on ports 0 and 2
-itmmask 0x5
3.8.3.5
-itmport
Defines the stimulus port from which SWO data is received and displayed by the SWO
Viewer. Default is stimulus port 0. The command line should look as below.
Syntax
-itmport
Example
-itmport 0
3.8.3.6
-outputfile
Define a file to which the output of SWO Viewer is printed.
Syntax
-outputfile
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Example
-outputfile “C:\Temp\Output.log”
3.8.3.7
-settingsfile
Select a J-Link settings file to use for the target device.
Syntax
-settingsfile
Example
-settingsfile “C:\Temp\Settings.jlink”
3.8.3.8
-swofreq
Defines the SWO frequency that shall be used by J-Link SWO Viewer for sampling SWO
data. Usually not necessary to define since optimal SWO speed is calculated automatically
based on the CPU frequency and the capabilities of the connected J-Link. If the targeted
SWO speed is 6 MHz the command line should look as follows.
Syntax
-swofreq
Example
-swofreq 6000000
3.8.3.9
-usb
Configures the connection settings according to defined USB S/N. Usually not necessary to
define if only one debug device is connected to the PC.
Syntax
-usb
Example
-usb 01234567
3.8.4
Configure SWO output after device reset
In some situations it might happen that the target application is reset and it is desired to log
the SWO output of the target after reset during the booting process. For such situations, the
target application itself needs to initialize the CPU for SWO output, since the SWO Viewer
is not restarted but continuously running.
Example code for enabling SWO out of the target application
#define ITM_ENA
#define ITM_TPR
(*(volatile unsigned int*)0xE0000E00) // ITM Enable
(*(volatile unsigned int*)0xE0000E40) // Trace Privilege
// Register
#define ITM_TCR
(*(volatile unsigned int*)0xE0000E80) // ITM Trace Control Reg.
#define ITM_LSR
(*(volatile unsigned int*)0xE0000FB0) // ITM Lock Status
// Register
#define DHCSR
(*(volatile unsigned int*)0xE000EDF0) // Debug register
#define DEMCR
(*(volatile unsigned int*)0xE000EDFC) // Debug register
#define TPIU_ACPR (*(volatile unsigned int*)0xE0040010) // Async Clock
// prescaler register
#define TPIU_SPPR (*(volatile unsigned int*)0xE00400F0) // Selected Pin Protocol
// Register
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#define DWT_CTRL
#define FFCR
(*(volatile unsigned int*)0xE0001000) // DWT Control Register
(*(volatile unsigned int*)0xE0040304) // Formatter and flush
// Control Register
U32 _ITMPort = 0; // The stimulus port from which SWO data is received
// and displayed.
U32 TargetDiv = 1; // Has to be calculated according to
// the CPU speed and the output baud rate
static void _EnableSWO() {
U32 StimulusRegs;
//
// Enable access to SWO registers
//
DEMCR |= (1 Run the JLink-plugin
configuration.
The screenshot below shows a debug session in IDE. For download and more information
about emIDE, please refer to http://emide.org .
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Console
GDB can be used stand-alone as a console application.
To connect GDB to GDB Server enter target remote localhost:2331 into the running
GDB. Within GDB all GDB commands and the remote monitor commands are available. For
more information about debugging with GDB refer to its online manual available at http://
sourceware.org/gdb/current/onlinedocs/gdb/ .
A typical startup of a debugging session can be like:
(gdb) file C:/temp/Blinky.elf
Reading symbols from C:/temp/Blinky.elf...done.
(gdb) target remote localhost:2331
Remote debugging using localhost:2331
0x00000000 in ?? ()
(gdb) monitor reset
Resetting target
(gdb) load
Loading section .isr_vector, size 0x188 lma 0x8000000
Loading section .text, size 0x568 lma 0x8000188
Loading section .init_array, size 0x8 lma 0x80006f0
Loading section .fini_array, size 0x4 lma 0x80006f8
Loading section .data, size 0x428 lma 0x80006fc
Start address 0x8000485, load size 2852
Transfer rate: 146 KB/sec, 570 bytes/write.
(gdb) break main
Breakpoint 1 at 0x800037a: file Src\main.c, line 38.
(gdb) continue
Continuing.
Breakpoint 1, main () at Src\main.c:38
38 Cnt = 0;
(gdb)
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Eclipse (CDT)
Eclipse is an open source platform-independent software framework, which has typically
been used to develop integrated development environment (IDE). Therefore Eclipse can be
used as C/C++ IDE, if you extend it with the CDT plug-in ( http://www.eclipse.org/cdt/ ).
CDT means “C/C++ Development Tooling” project and is designed to use the GDB as default
debugger and works without any problems with the GDB Server. Refer to http://www.eclipse.org for detailed information about Eclipse.
Note
We only support problems directly related to the GDB Server. Problems and questions
related to your remaining toolchain have to be solved on your own.
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4.3
Supported remote (monitor) commands
Supported remote (monitor) commands
J-Link GDB Server comes with some functionalities which are not part of the standard GDB.
These functions can be called either via a gdbinit file passed to GDB Server or via monitor
commands passed directly to GDB, forwarding them to GDB Server.
To indicate to GDB to forward the command to GDB Server ’monitor’ has to be prepended
to the call. For example a reset can be triggered in the gdbinit file with “reset” or via GDB
with “monitor reset”.
The following remote commands are available:
Remote command
Explanation
clrbp
Removes an instruction breakpoint.
cp15
Reads or writes from/to cp15 register.
device
Select the specified target device.
DisableChecks
Do not check if an abort occurred after memory read
(ARM7/9 only).
EnableChecks
Check if an abort occurred after memory read (ARM7/9 only).
flash breakpoints
Enables/Disables flash breakpoints.
flash erase
Erases the flash memory of the target device.
getargs
Get the arguments for the application.
go
Starts the target CPU.
halt
Halts the target CPU.
jtagconf
Configures a JTAG scan chain with multiple devices on it.
memU8
Reads or writes a byte from/to given address.
memU16
Reads or writes a halfword from/to given address.
memU32
Reads or writes a word from/to given address.
reg
Reads or writes from/to given register.
regs
Reads and displays all CPU registers.
reset
Resets and halts the target CPU.
semihosting breakOnError
Enable or disable halting the target on semihosting error.
semihosting enable
Enables semihosting.
semihosting IOClient
Set semihosting I/O to be handled via Telnet port or GDB.
semihosting ARMSWI
Sets the SWI number used for semihosting in ARM mode.
semihosting ThumbSWI
Sets the SWI number used for semihosting in thumb mode.
setargs
Set the arguments for the application.
setbp
Sets an instruction breakpoint at a given address.
sleep
Sleeps for a given time period.
speed
Sets the JTAG speed of J-Link / J-Trace.
step
Performs one or more single instruction steps.
SWO DisableTarget
Undo target configuration for SWO and disable it in J-Link.
SWO EnableTarget
Configure target for SWO and enable it in J-Link.
SWO GetMaxSpeed
Prints the maximum supported SWO speed for J-Link and
Target CPU.
SWO GetSpeedInfo
Prints the available SWO speed and its minimum divider.
waithalt
Waits for target to halt code execution.
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Remote command
Supported remote (monitor) commands
Explanation
wice
Writes to given IceBreaker register.
ReadAP
Reads the specified CoreSight DAP-AP register.
ReadDP
Reads the specified CoreSight DAP-DP register.
WriteAP
Writes the specified CoreSight DAP-AP register.
WriteDP
Writes the specified CoreSight DAP-DP register.
The Following remote commands are deprecated and only available for backward compatibility:
Remote command
Explanation
device
Selects the specified target device.
Note: Use command line option -device instead.
interface
Selects the target interface.
Note: Use command line option -if instead.
speed
Sets the JTAG speed of J-Link / J-Trace.
Note: For the initial connection speed, use command line
option -speed instead.
Note
The remote commands are case-insensitive.
Note
Optional parameters are set into square brackets.
Note
The examples are described as follows:
Lines starting with ’#’ are comments and not used in GDB / GDB Server.
Lines starting with ’>’ are input commands from the GDB.
Lines starting with ’ monitor clrbp 1
> monitor ci 1
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4.3.2
Supported remote (monitor) commands
cp15
Reads or writes from/to cp15 register. If is specified, this command writes the data
to the cp15 register. Otherwise this command reads from the cp15 register. For further
information please refer to the ARM reference manual.
Syntax
cp15 , , , [= ]
The parameters of the function are equivalent to the MCR instructions described in the ARM
documents.
Example
#Read:
> monitor cp15 1, 2, 6, 7
< Reading CP15 register (1,2,6,7 = 0x0460B77D)
#Write:
> monitor cp15 1, 2, 6, 7 = 0xFFFFFFFF
4.3.3
device
Note
Deprecated. Use command line option -device instead.
Selects the specified target device. This is necessary for the connection and some special
handling of the device.
Note
The device should be selected via commandline option -device when starting GDB
Server.
Syntax
device
Example
> monitor device STM32F417IG
< Selecting device: STM32F417IG
4.3.4
DisableChecks
Disables checking if a memory read caused an abort (ARM7/9 devices only). On some CPUs
during the init sequence for enabling access to the internal memory (for example on the
TMS470) some dummy reads of memory are required which will cause an abort as long as
the access-init is not completed.
Syntax
DisableChecks
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4.3.5
Supported remote (monitor) commands
EnableChecks
Enables checking if a memory read caused an abort (ARM7/9 devices only). On some CPUs
during the init sequence for enabling access to the internal memory (for example on the
TMS470) some dummy reads of memory are required which will cause an abort as long as
the access-init is not completed. The default state is: Checks enabled.
Syntax
EnableChecks
4.3.6
flash breakpoints
This command enables/disables the Flash Breakpoints feature. By default Flash Breakpoints
are enabled and can be used for evaluation.
Syntax
monitor flash breakpoints =
Example
#Disable Flash Breakpoints:
> monitor flash breakpoints = 0
< Flash breakpoints disabled
#Enable Flash Breakpoins:
> monitor flash breakpoints = 1
< Flash breakpoints enabled
4.3.7
flash erase
This command erases the flash memory of the target device.
Syntax
flash erase
4.3.8
getargs
Get the currently set argument list which will be given to the application when calling
semihosting command SYS_GET_CMDLINE (0x15). The argument list is given as one string.
Syntax
getargs
Example
#No arguments set via setargs:
> monitor getargs
< No arguments.
#Arguments set via setargs:
> monitor getargs
< Arguments: test 0 1 2 arg0=4
4.3.9
go
Starts the target CPU.
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Supported remote (monitor) commands
Syntax
go
Example
> monitor go
4.3.10
halt
Halts the target CPU.
Syntax
halt
Example
> monitor halt
4.3.11
interface
Note
Deprecated. Use command line option -if instead.
Selects the target interface used by J-Link / J-Trace.
Syntax
interface
4.3.12
jtagconf
Configures a JTAG scan chain with multiple devices on it. is the sum of IRLens of all
devices closer to TDI, where IRLen is the number of bits in the IR (Instruction Register) of
one device. is the number of devices closer to TDI. For more detailed information
of how to configure a scan chain with multiple devices please refer to Determining values
for scan chain configuration .
Note
To make sure the connection to the device can be established correctly, it is recommended to configure the JTAG scan chain via command line options at the start of
GDB Server.
Syntax
jtagconf
Example
#Select the second device, where there is 1 device in front with IRLen 4
> monitor jtagconf 4 1
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4.3.13
Supported remote (monitor) commands
memU8
Reads or writes a byte from/to a given address. If is specified, this command writes
the value to the given address. Otherwise this command reads from the given address.
Syntax
memU8 [= ]
Example
#Read:
> monitor memU8 0x50000000
< Reading from address 0x50000000 (Data = 0x04)
#Write:
> monitor memU8 0x50000000 = 0xFF
< Writing 0xFF @ address 0x50000000
4.3.14
memU16
Reads or writes a halfword from/to a given address. If is specified, this command
writes the value to the given address. Otherwise this command reads from the given address.
Syntax
memU16 [= ]
Example
#Read:
> monitor memU16 0x50000000
< Reading from address 0x50000000 (Data = 0x3004)
#Write:
> monitor memU16 0x50000000 = 0xFF00
< Writing 0xFF00 @ address 0x50000000
4.3.15
memU32
Reads or writes a word from/to a given address. If is specified, this command writes
the value to the given address. Otherwise this command reads from the given address.
This command is similar to the long command.
Syntax
memU32 [= ]
Example
#Read:
> monitor memU32 0x50000000
< Reading from address 0x50000000 (Data = 0x10023004)
#Write:
> monitor memU32 0x50000000 = 0x10023004
< Writing 0x10023004 @ address 0x50000000
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4.3.16
Supported remote (monitor) commands
reg
Reads or writes from/to given register. If is specified, this command writes the
value into the given register. If is specified, this command writes the memory
content at address to register . Otherwise this command reads the
given register.
Syntax
reg [= ]
or
reg [= ()]
Example
#Write value to register:
> monitor reg pc = 0x00100230
< Writing register (PC = 0x00100230)
#Write value from address to register:
> monitor reg r0 = (0x00000040)
< Writing register (R0 = 0x14813004)
#Read register value:
> monitor reg PC
< Reading register (PC = 0x00100230)
4.3.17
regs
Reads all CPU registers.
Syntax
regs
Example
> monitor regs
< PC = 00100230, CPSR = 20000013 (SVC mode, ARM)
R0 = 14813004, R1 = 00000001, R2 = 00000001, R3 = 000003B5
R4 = 00000000, R5 = 00000000, R6 = 00000000, R7 = 00000000
USR: R8 =00000000, R9 =00000000, R10=00000000, R11 =00000000, R12 =00000000
R13=00000000, R14=00000000
FIQ: R8 =00000000, R9 =00000000, R10=00000000, R11 =00000000, R12 =00000000
R13=00200000, R14=00000000, SPSR=00000010
SVC: R13=002004E8, R14=0010025C, SPSR=00000010
ABT: R13=00200100, R14=00000000, SPSR=00000010
IRQ: R13=00200100, R14=00000000, SPSR=00000010
UND: R13=00200100, R14=00000000, SPSR=00000010
4.3.18
reset
Resets and halts the target CPU. Make sure the device is selected prior to using this command to make use of the correct reset strategy.
Note
There are different reset strategies for different CPUs. Moreover, the reset strategies
which are available differ from CPU core to CPU core. J-Link can perform various reset
strategies and always selects the best fitting strategy for the selected device.
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Syntax
reset
Example
> monitor reset
< Resetting target
4.3.19
semihosting breakOnError
Enables or disables halting the target at the semihosting breakpoint / in SVC handler if an error occurred during a semihosting command, for example a bad file handle for SYS_WRITE.
The GDB Server log window always shows a warning in these cases. breakOnError is disabled by default.
Syntax
semihosting breakOnerror
Example
#Enable breakOnError:
> monitor semihosting breakOnError 1
4.3.20
semihosting enable
Enables semihosting with the specified vector address. If no vector address is specified,
the SWI vector (at address 0x8) will be used. GDBServer will output semihosting terminal
data from the target via a separate connection on port 2333. Some IDEs already establish
a connection automatically on this port and show terminal data in a specific window in the
IDE. For IDEs which do not support semihosting terminal output directly, the easiest way
to view semihosting output is to open a telnet connection to the GDBServer on port 2333.
The connection on this port can be opened all the time as soon as GDBServer is started,
even before this remote command is executed.
Syntax
semihosting enable []
Example
> monitor semihosting enable
< Semihosting enabled (VectorAddr = 0x08)
4.3.21
semihosting IOClient
GDB itself can handle (file) I/O operations, too. With this command it is selected whether
to print output via TELNET port (2333), GDB, or both.
is
•
•
•
1 for TELNET Client (Standard port 2333) (Default)
2 for GDB Client
or 3 for both (Input via GDB Client)
Syntax
semihosting IOClient
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Supported remote (monitor) commands
Example
#Select TELNET port as output source
> monitor semihosting ioclient 1
< Semihosting I/O set to TELNET Client
#Select GDB as output source
> monitor semihosting ioclient 2
< Semihosting I/O set to GDB Client
#Select TELNET port and GDB as output source
> monitor semihosting ioclient 3
< Semihosting I/O set to TELNET and GDB Client
4.3.22
semihosting ARMSWI
Sets the SWI number used for semihosting in ARM mode. The default value for the ARMSWI
is 0x123456.
Syntax
semihosting ARMSWI
Example
> monitor semihosting ARMSWI 0x123456
< Semihosting ARM SWI number set to 0x123456
4.3.23
semihosting ThumbSWI
Sets the SWI number used for semihosting in thumb mode. The default value for the ThumbSWI is 0xAB
Syntax
semihosting ThumbSWI
Example
> monitor semihosting ThumbSWI 0xAB
< Semihosting Thumb SWI number set to 0xAB
4.3.24
setargs
Set arguments for the application, where all arguments are in one separated by whitespaces. The argument string can be gotten by the application via semihosting command SYS_GET_CMDLINE (0x15). Semihosting has to be enabled for getting the
argumentstring (see semihosting enable ). “monitor setargs” can be used before enabling
semihosting. The maximum length for is 512 characters.
Syntax
setargs
Example
> monitor setargs test 0 1 2 arg0=4
< Arguments: test 0 1 2 arg0=4
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4.3.25
Supported remote (monitor) commands
setbp
Sets an instruction breakpoint at the given address, where can be 0x03 for ARM
instruction breakpoints (Instruction width 4 Byte, mask out lower 2 bits) or 0x01 for THUMB
instruction breakpoints (Instruction width 2 Byte, mask out lower bit). If no mask is given,
an ARM instruction breakpoint will be set.
Syntax
setbp []
Example
#Set a breakpoint (implicit for ARM instructions)
> monitor setbp 0x00000000
#Set a breakpoint on a THUMB instruction
> monitor setbp 0x00000100 0x01
4.3.26
sleep
Sleeps for a given time, where is the time period in milliseconds to delay. While
sleeping any communication is blocked until the command returns after the given period.
Syntax
sleep
Example
> monitor sleep 1000
< Sleep 1000ms
4.3.27
speed
Note
Deprecated. For setting the initial connection speed, use command line option -speed
instead.
Sets the JTAG speed of J-Link / J-Trace. Speed can be either fixed (in kHz), automatic
recognition or adaptive. In general, Adaptive is recommended if the target has an RTCK
signal which is connected to the corresponding RTCK pin of the device (S-cores only). For
detailed information about the different modes, refer to JTAG Speed . The speed has to be
set after selecting the interface, to change it from its default value.
Syntax
speed |auto|adaptive
Example
> monitor speed auto
< Select auto target interface speed (8000 kHz)
> monitor speed 4000
< Target interface speed set to 4000 kHz
> monitor speed adaptive
< Select adaptive clocking instead of fixed JTAG speed
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4.3.28
Supported remote (monitor) commands
step
Performs one or more single instruction steps, where is the number of instruction steps to perform. If is not specified only one instruction step will
be performed.
Syntax
step []
or
si []
Example
> monitor step 3
4.3.29
SWO DisableTarget
Disables the output of SWO data on the target (Undoes changes from SWO EnableTarget)
and stops J-Link to capture it.
Syntax
SWO DisableTarget
Example
#Disable capturing SWO from stimulus ports 0 and 1
> monitor SWO DisableTarget 3
< SWO disabled successfully.
4.3.30
SWO EnableTarget
Configures the target to be able to output SWO data and starts J-Link to capture it. CPU
and SWO frequency can be 0 for auto-detection.
If CPUFreq is 0, J-Link will measure the current CPU speed.
If SWOFreq is 0, J-Link will use the highest available SWO speed for the selected / measured
CPU speed.
Note
CPUFreq has to be the speed at which the target will be running when doing SWO. If
the speed is different from the current speed when issuing CPU speed auto-detection,
getting SWO data might fail. SWOFreq has to be a quotient of the CPU and SWO speeds
and their prescalers. To get available speed, use SWO GetSpeedInfo. PortMask can
be a decimal or hexadecimal Value. Values starting with the Prefix “0x” are handled
hexadecimal.
Syntax
SWO EnableTarget
monitor SWO EnableTarget 0 0 1 0
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< SWO enabled successfully.
#Configure SWO for stimulus ports 0-2, fixed SWO frequency and measure CPU
frequency
> monitor SWO EnableTarget 0 1200000 5 0
< SWO enabled successfully.
#Configure SWO for stimulus ports 0-255, fixed CPU and SWO frequency
> monitor SWO EnableTarget 72000000 6000000 0xFF 0
< SWO enabled successfully.
4.3.31
SWO GetMaxSpeed
Prints the maximum SWO speed supported by and matching both, J-Link and the target
CPU frequency.
Syntax
SWO GetMaxSpeed
Example
#Get SWO speed for 72MHz CPU speed
> monitor SWO GetMaxSpeed 72000000
< Maximum supported SWO speed is 6000000 Hz.
4.3.32
SWO GetSpeedInfo
Prints the base frequency and the minimum divider of the connected J-Link. With this
information, the available SWO speeds for J-Link can be calculated and the matching one
for the target CPU frequency can be selected.
Syntax
SWO GetSpeedInfo
Example
> monitor SWO GetSpeedInfo
< Base frequency: 60000000Hz, MinDiv: 8
# Available SWO speeds for J-Link are: 7.5MHz, 6.66MHz, 6MHz, ...
4.3.33
waithalt
Waits for target to halt code execution, where is the maximum time period in
milliseconds to wait.
Syntax
waithalt
or
wh
Example
#Wait for halt with a timeout of 2 seconds
> monitor waithalt 2000
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4.3.34
Supported remote (monitor) commands
wice
Writes to given IceBreaker register, where is the data to write.
Syntax
wice
or
rmib
Example
> monitor wice 0x0C 0x100
4.3.35
ReadAP
Reads the specified CoreSight DAP-AP register.
Note
- ARM specifies register addresses for JTAG (0x0, 0x4, 0x8, …) and register indexes
for SWD (0, 1, 2, …).
This API always works with register indexes, so:
- Addr 0x0 = RegIndex 0
- Addr 0x4 = RegIndex 1
- Addr 0x8 = RegIndex 2
- Addr 0xC = RegIndex 3
- In case a WAIT response is received from the DAP, J-Link will retry the access until
OK/FAULT is received or the operation times out (100ms).
- Performs a fully qualified read. This means that for AP accesses which are “registered”, J-Link performs an implicit read of AP-RDBUFF after the AP access, to get the
actual value.
Syntax
ReadAP []
Example
>
>
<
>
>
<
# Select AP[0] (AHB-AP) AP bank 0
monitor WriteDP 2 0x00000000
O.K.
# Read AHB-AP TAR
monitor ReadAP 1
O.K.:0x08000000
4.3.36
ReadDP
Reads the specified CoreSight DAP-DP register.
Note
- ARM specifies register addresses for JTAG (0x0, 0x4, 0x8, …) and register indexes
for SWD (0, 1, 2, …).
This API always works with register indexes, so:
- Addr 0x0 = RegIndex 0
- Addr 0x4 = RegIndex 1
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- Addr 0x8 = RegIndex 2
- Addr 0xC = RegIndex 3
- In case a WAIT response is received from the DAP, J-Link will retry the access until
OK/FAULT is received or the operation times out (100ms).
- Performs a fully qualified read. This means that for AP accesses which are “registered”, J-Link performs an implicit read of DP-RDBUFF after the DP access, to get the
actual value.
Syntax
ReadDP []
Example
> # Read CTRL/STAT
> monitor ReadDP 1
< O.K.:0xF0000000
4.3.37
WriteAP
Writes the specified CoreSight DAP-AP register.
Note
- ARM specifies register addresses for JTAG (0x0, 0x4, 0x8, …) and register indexes
for SWD (0, 1, 2, …).
This API always works with register indexes, so:
- Addr 0x0 = RegIndex 0
- Addr 0x4 = RegIndex 1
- Addr 0x8 = RegIndex 2
- Addr 0xC = RegIndex 3
- In case a WAIT response is received from the DAP, J-Link will retry the access until
OK/FAULT is received or the operation times out (100ms).
Syntax
WriteAP [, ]
Example
>
>
<
>
>
<
# Select AP[0] (AHB-AP) AP bank 0
monitor WriteDP 2 0x00000000
O.K.
# Write AHB-AP TAR
monitor WriteAP 1 0x08000000
O.K.
4.3.38
WriteDP
Writes the specified CoreSight DAP-DP register.
Note
- ARM specifies register addresses for JTAG (0x0, 0x4, 0x8, …) and register indexes
for SWD (0, 1, 2, …).
This API always works with register indexes, so:
- Addr 0x0 = RegIndex 0
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- Addr 0x4 = RegIndex 1
- Addr 0x8 = RegIndex 2
- Addr 0xC = RegIndex 3
- In case a WAIT response is received from the DAP, J-Link will retry the access until
OK/FAULT is received or the operation times out (100ms).
Syntax
WriteDP [, ]
Example
> # Write SELECT register: Select AP[0] (AHB-AP) AP bank 15
> monitor WriteDP 2 0x000000F0
< O.K.
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4.4
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SEGGER-specific GDB protocol extensions
SEGGER-specific GDB protocol extensions
J-Link GDB Server implements some functionality which are not part of the standard GDB
remote protocol in general query packets. These SEGGER-specific general query packets
can be sent to GDB Server on the low-level of GDB, via maintenance commands, or with
a custom client connected to GDB Server.
As these extensions are not of interest for the regular user, they have been added to a
separate manual that describes the SEGGER-specific GDB protocol extensions that have
been added to J-Link GDB Server. The manual is available for download on the SEGGER
website: UM08036
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4.5
Command line options
Command line options
There are several command line options available for the GDB Server which allow configuration of the GDB Server before any connection to a J-Link is attempted or any connection
from a GDB client is accepted.
Note
Using GDB Server CL, device, interface, endian and speed are mandatory options
to correctly connect to the target, and should be given before connection via GDB.
Using GDB Server GUI the mandatory options can also be selected in the configuration
dialog.
Command line option
Explanation
-device
Selects the connected target device.
-endian
Selects the device endianness.
-if
Selects the interface to connect to the target.
-speed
Selects the target communication speed.
Note
Using multiple instances of GDB Server, setting custom values for port, SWOPort and
TelnetPort is necessary.
Command line option
Explanation
-port
Select the port to listen for GDB clients.
-swoport
Select the port to listen for clients for SWO RAW output.
-telnetport
Select the port to listen for clients for printf output.
The GDB Server GUI version uses persistent settings which are saved across different instances and sessions of GDB Server. These settings can be toggled via the checkboxes in
the GUI.
Note
GDB Server CL always starts with the settings marked as default.
For GUI and CL, the settings can be changed with following command line options. For all
persistent settings there is a pair of options to enable or disable the feature.
Command line option
Explanation
-ir
Initialize the CPU registers on start of GDB Server. (Default)
-noir
Do not initialize CPU registers on start of GDB Server.
-localhostonly
Allow only localhost connections (Windows default)
-nolocalhostonly
Allow connections from outside localhost (Linux default)
-logtofile
Generate a GDB Server log file.
-nologtofile
Do not generate a GDB Server log file. (Default)
-halt
Halt the target on start of GDB Server. (Default)
-nohalt
Do not halt the target on start of GDB Server.
-silent
Do not show log output.
-nosilent
Show log output. (Default)
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Command line option
Command line options
Explanation
-stayontop
Set the GDB Server GUI to be the topmost window.
-nostayontop
Do not be the topmost window. (Default)
-timeout
Set the time after which the target has to be connected.
-notimeout
Set infinite timeout for target connection.
-vd
Verify after downloading.
-novd
Do not verify after downloading. (Default)
Following additional command line options are available. These options are temporary for
each start of GDB Server.
Command line option
Explanation
-excdbg
Enable exception debugging.
-jtagconf
Configures a JTAG scan chain with multiple devices on it.
-log
Logs the GDB Server communication to a specific file.
-rtos
Selects a RTOS plugin (DLL file)
-singlerun
Starts GDB Server in single run mode.
-s
Same as -singlerun
-nosinglerun
Starts GDB Server in no single run mode. (Default)
-nos
Same as -nosinglerun
-noreset
Starts GDB Server in no reset mode.
-JLinkDevicesXMLPath
Specifies a search path where to look for a file that might specify additional devices
-powertarget
Power target after specified delay (1-9). 0 turns off power.
-gui
Do not suppress DLL dialogs. (Default)
-nogui
Suppress DLL Dialogs.
-jlinkscriptfile
Specifies a J-Link script file.
-select
Selects the interface to connect to J-Link (USB/IP).
-settingsfile
Selects the J-Link Settings File.
-strict
Starts GDB Server in strict mode.
-x
Executes a gdb file on first connection.
-xc
Executes a gdb file on every connection.
-cpu
Selects the CPU core. Deprecated, use -device instead.
4.5.1
-cpu
Pre-select the CPU core of the connected device, so the GDB Server already knows the
register set, even before having established a connection to the CPU.
Note
Deprecated, please use -device instead. Anyhow, it does not hurt if this option is set,
too.
Syntax
-CPU
Example
jlinkgdbserver -CPU ARM7_9
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Add. information
The following table lists all valid values for :
Supported CPU cores
CPU_FAMILY_ARM7_9
Pre-select ARM7 and ARM9 as CPU cores.
CPU_FAMILY_CORTEX_A_R
Pre-select Cortex-A and Cortex-R as CPU cores.
CPU_FAMILY_CORTEX_M
Pre-select Cortex-M as CPU core.
CPU_FAMILY_RX600
Pre-select Renesas RX600 as CPU core.
4.5.2
-device
Tells GDBServer to which device J-Link is connected before the connect sequence is actually
performed. It is recommended to use the command line option to select the device instead
of using the remote command since for some devices J-Link already needs to know the
device at the time of connecting to it since some devices need special connect sequences
(e.g. devices with TI ICEPick modules). In such cases, it is not possible to select the device
via remote commands since they are configured after the GDB client already connected
to GDBServer and requested the target registers which already requires a connection to
the target.
Note
Using GDB Server CL this option is mandatory to correctly connect to the target, and
should be given before connection via GDB.
Syntax
-device
Example
jlinkgdbserver -device AT91SAM7SE256
Add. information
For a list of all valid values for , please refer to List of supported target
devices .
4.5.3
-endian
Sets the endianness of the target where endianness can either be “little” or “big”.
Syntax
-endian
Example
jlinkgdbserver -endian little
Note
When using GDB Server CL this option is mandatory to correctly connect to the target,
and should be given before connection via GDB.
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4.5.4
Command line options
-gui
Do not suppress DLL dialogs.
Syntax
-gui
Example
jlinkgdbserver -gui
4.5.5
-if
Selects the target interface which is used by J-Link to connect to the device. The default
value is JTAG.
Syntax
-if
Example
jlinkgdbserver -if SWD
Add. information
Currently, the following values are accepted for :
•
•
•
•
JTAG
SWD
FINE
2-wire-JTAG-PIC32
4.5.6
-ir
Initializes the CPU register with default values on startup.
Note
For the GUI version, this setting is persistent for following uses of GDB Server until
changed via -noir or the GUI.
Example
jlinkgdbserver -ir
4.5.7
-excdbg
Enables exception debugging. Exceptions on ARM CPUs are handled by exception handlers.
Exception debugging makes the debugging of exceptions more user-friendly by passing a
signal to the GDB client and returning to the causative instruction. In order to do this, a
special exception handler is required as follows:
__attribute((naked)) void OnHardFault(void){
__asm volatile (
" bkpt 10 \n"
" bx lr \n"
);
}
The signal passed to the GDB client is the immediate value (10 in the example) of the
software breakpoint instruction. specifies, how many instructions need to be
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executed until the exception return occurs. In most cases this will be 2 (which is the default
value), if the handler function is set as the exception handler. If it is called indirectly as a
subroutine from the exception handler, there may be more steps required. It is mandatory
to have the function declared with the “naked” attribute and to have the bx lr instruction
immediately after the software breakpoint instruction. Otherwise the software breakpoint
will be treated as a usual breakpoint.
Syntax
-excdbg
Example
jlinkgdbserver -excdbg 4
4.5.8
-jtagconf
Configures a JTAG scan chain with multiple devices on it. is the sum of IRLens of all
devices closer to TDI, where IRLen is the number of bits in the IR (Instruction Register) of
one device. is the number of devices closer to TDI. For more detailed information
of how to configure a scan chain with multiple devices please refer to Determining values
for scan chain configuration .
Syntax
-jtagconf ,
Example
#Select the second device, where there is 1 device in front with IRLen 4
jlinkgdbserver -jtagconf 4,1
4.5.9
-localhostonly
Starts the GDB Server with the option to listen on localhost only (This means that only TCP/
IP connections from localhost are accepted) or on any IP address. To allow remote debugging (connecting to GDBServer from another PC), deactivate this option. If no parameter
is given, it will be set to 1 (active).
Note
For the GUI version, this setting is persistent for following uses of GDB Server until
changed via command line option or the GUI.
Syntax
-LocalhostOnly
Example
jlinkgdbserver -LocalhostOnly 0 //Listen on any IP address (Linux/MAC default)
jlinkgdbserver -LocalhostOnly 1 //Listen on localhost only (Windows default)
4.5.10
-log
Starts the GDB Server with the option to write the output into a given log file. The file
will be created if it does not exist. If it exists the previous content will be removed. Paths
including spaces need to be set between quotes.
Syntax
-log
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Example
jlinkgdbserver -log “C:\my path\to\file.log”
4.5.11
-logtofile
Starts the GDB Server with the option to write the output into a log file. If no file is given
via -log , the log file will be created in the GDB Server application directory.
Note
For the GUI version, this setting is persistent for following uses of GDB Server until
changed via -nologtofile or the GUI.
Syntax
logtofile
Example
jlinkgdbserver -logtofile
jlinkgdbserver -logtofile -log “C:\my path\to\file.log”
4.5.12
-halt
Halts the target after connecting to it on start of GDB Server. For most IDEs this option is
mandatory since they rely on the target to be halted after connecting to GDB Server.
Note
For the GUI version, this setting is persistent for following uses of GDB Server until
changed via -nohalt or the GUI.
Syntax
-halt
Example
jlinkgdbserver -halt
4.5.13
-nogui
Suppresses DLL dialogs.
Syntax
-nogui
Example
jlinkgdbserver -nogui
4.5.14
-noir
Do not initialize the CPU registers on startup.
Note
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For the GUI version, this setting is persistent for following uses of GDB Server until
changed via -ir or the GUI.
Syntax
noir
4.5.15
-nolocalhostonly
Starts GDB Server with the option to allow remote connections (from outside localhost).
Same as -localhostonly 0
Note
For the GUI version, this setting is persistent for following uses of GDB Server until
changed via command line option or the GUI.
Syntax
-nolocalhostonly
4.5.16
-nologtofile
Starts the GDB Server with the option to not write the output into a log file.
Note
For the GUI version, this setting is persistent for following uses of GDB Server until
changed via -nologtofile or the GUI. When this option is used after -log, no log file
will be generated, when -log is used after this option, a log file will be generated and
this setting will be overridden.
Syntax
-nologtofile
Example
jlinkgdbserver -nologtofile // Will not generate a log file
jlinkgdbserver -nologtofile -log “C:\pathto\file.log” // Will generate a log
file
jlinkgdbserver -log “C:\pathto\file.log” -nologtofile // Will not generate
a log file
4.5.17
-nohalt
When connecting to the target after starting GDB Server, the target is not explicitly halted and the CPU registers will not be inited. After closing all GDB connections the target
is started again and continues running. Some IDEs rely on the target to be halted after
connect. In this case do not use -nohalt, but -halt.
Note
For the GUI version, this setting is persistent for following uses of GDB Server until
changed via -halt or the GUI.
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Syntax
-nohalt
Example
jlinkgdbserver -nohalt
4.5.18
-noreset
Perform no reset on connect, just halt the CPU
Syntax
-noreset
Example
jlinkgdbserver -norest
4.5.19
-nosinglerun
Single run mode turned off. (Default)
Syntax
-nosinglerun
Example
jlinkgdbserver -nosinglerun
4.5.20
-nosilent
Starts the GDB Server in non-silent mode. All log window messages will be shown.
Note
For the GUI version, this setting is persistent for following uses of GDB Server until
changed via command line option or the GUI.
Syntax
-nosilent
Example
jlinkgdbserver -nosilent
4.5.21
-nostayontop
Starts the GDB Server in non-topmost mode. All windows can be placed above it.
Note
For the CL version this setting has no effect. For the GUI version, this setting is persistent for following uses of GDB Server until changed via command line option or
the GUI.
Syntax
-nostayontop
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Example
jlinkgdbserver -nostayontop
4.5.22
-notimeout
GDB Server automatically closes after a timeout of 5 seconds when no target voltage can
be measured or connection to target fails. This command line option prevents GDB Server
from closing, to allow connecting a target after starting GDB Server.
Note
The recommended order is to power the target, connect it to J-Link and then start
GDB Server.
Syntax
-notimeout
4.5.23
-novd
Do not explicitly verify downloaded data.
Note
For the GUI version, this setting is persistent for following uses of GDB Server until
changed via command line option or the GUI.
Syntax
-novd
4.5.24
-port
Starts GDB Server listening on a specified port. This option overrides the default listening
port of the GDB Server. The default port is 2331.
Note
Using multiple instances of GDB Server, setting custom values for this option is necessary.
Syntax
-port
Example
jlinkgdbserver -port 2345
4.5.25
-rtos
Specifies a RTOS plug-in (.DLL file for Windows, .SO file for Linux and Mac). If the file-name
extension is not specified, it is automatically added depending on the PC’s operating system.
The J-Link Software and Documentation Package comes with RTOS plug-ins for embOS
and FreeRTOS pre-installed in the sub-directory “GDBServer”. A software development kit
(SDK) for creating your own plug-ins is also available upon request on our website (https://
www.segger.com/downloads/jlink/#gdbserver_rtos).
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Syntax
-rtos [.dll|.so]
Example
jlinkgdbserver -rtos GDBServer\RTOSPlugin_embOS
4.5.26
-JLinkDevicesXMLPath
Specifies a search path where to look for a file. The given path may be
absolute or relative to the location of the JLinkARM.dll. This is mainly used for preliminary /
special devices where a vendor ships a file to specific customers and
this file defines new devices that are not publicly available yet.
Syntax
-JLinkDevicesXMLPath
Example
jlinkgdbserver -JLinkDevicesXMLPath C:\Work\MyDevices\
4.5.27
-jlinkscriptfile
Passes the path of a J-Link script file to the GDB Server. This scriptfile is executed before
the GDB Server starts the debugging / identifying communication with the target. J-Link
scriptfiles are mainly used to connect to targets which need a special connection sequence
before communication with the core is possible. For more information about J-Link script
files, please refer to J-Link script files .
Syntax
-jlinkscriptfile
Example
-jlinkscriptfile “C:\My Projects\Default.JLinkScript”
4.5.28
-powertarget
Power target after specified delay (1-9 ms). 0 turns off power.
Syntax
-powertarget
Value can can range from 0-9.
Example
jlinkgdbserver -powertarget 1
4.5.29
-select
Specifies the host interface to be used to connect to J-Link. Currently, USB and TCP/IP
are available.
Syntax
-select Settings > Control Panel > Add/
Remove Programs ) select Windows Driver Package - Segger (jlink) USB and click the
Change/Remove button.
3. Confirm the uninstallation process.
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6.3
Setting up the IP interface
Setting up the IP interface
Some emulators of the J-Link family have (or future members will have) an additional
Ethernet interface, to communicate with the host system. These emulators will also come
with a built-in web server which allows configuration of the emulator via web interface. In
addition to that, you can set a default gateway for the emulator which allows using it even
in large intranets. For simplicity the setup process of J-Link Pro (referred to as J-Link) is
described in this section.
6.3.1
Configuring J-Link using J-Link Configurator
The J-Link Software and Documentation Package comes with a free GUI-based utility called
J-Link Configurator which auto-detects all J-Links that are connected to the host PC via
USB & Ethernet. The J-Link Configurator allows the user to setup the IP interface of JLink. For more information about how to use the J-Link Configurator, please refer to JLink Configurator .
6.3.2
Configuring J-Link using the webinterface
All emulators of the J-Link family which come with an Ethernet interface also come with
a built-in web server, which provides a web interface for configuration. This enables the
user to configure J-Link without additional tools, just with a simple web browser. The Home
page of the web interface shows the serial number, the current IP address and the MAC
address of the J-Link.
The Network configuration page allows configuration of network related settings (IP address, subnet mask, default gateway) of J-Link. The user can choose between automatic
IP assignment (settings are provided by a DHCP server in the network) and manual IP
assignment by selecting the appropriate radio button.
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Setting up the IP interface
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6.4
CHAPTER 6
FAQs
FAQs
Q: How can I use J-Link with GDB and Ethernet?
A: You have to use the J-Link GDB Server in order to connect to J-Link via GDB and
Ethernet.
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6.5
J-Link Configurator
J-Link Configurator
Normally, no configuration is required, especially when using J-Link via USB. For special
cases like having multiple older J-Links connected to the same host PC in parallel, they need
to be re-configured to be identified by their real serial number when enumerating on the
host PC. This is the default identification method for current J-Links (J-Link with hardware
version 8 or later). For re-configuration of old J-Links or for configuration of the IP settings
(use DHCP, IP address, subnet mask, …) of a J-Link supporting the Ethernet interface,
SEGGER provides a GUI-based tool, called J-Link Configurator. The J-Link Configurator is
part of the J-Link Software and Documentation Package and can be used free of charge.
6.5.1
Configure J-Links using the J-Link Configurator
A J-Link can be easily configured by selecting the appropriate J-Link from the emulator list
and using right click -> Configure.
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J-Link Configurator
In order to configure an old J-Link, which uses the old USB 0 - 3 USB identification method,
to use the new USB identification method (reporting the real serial number) simply select
“Real SN” as USB identification method and click the OK button. The same dialog also allows
configuration of the IP settings of the connected J-Link if it supports the Ethernet interface.
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6.6
J-Link USB identification
J-Link USB identification
In general, when using USB, there are two ways in which a J-Link can be identified:
•
•
By serial number
By USB address
Default configuration of J-Link is: Identification by serial number. Identification via USB
address is used for compatibility and not recommended.
Background information
“USB address” really means changing the USB-Product ID (PID). The following table shows
how J-Links enumerate in the different identification modes.
Identification
PID
Serial number
Serial number (default)
0x0101
Serial number is real serial number
of the J-Link or user assigned.
USB address 0 (Deprecated)
0x0101
123456
USB address 1 (Deprecated)
0x0102
123456
USB address 2 (Deprecated)
0x0103
123456
USB address 3 (Deprecated)
0x0104
123456
6.6.1 Connecting to different J-Links connected to the same
host PC via USB
In general, when having multiple J-Links connected to the same PC, the J-Link to connect
to is explicitly selected by its serial number. Most software/debuggers provide an extra field
to type-in the serial number of the J-Link to connect to.
A debugger / software which does not provide such a functionality, the J-Link DLL automatically detects that multiple J-Links are connected to the PC and shows a selection dialog
which allows the user to select the appropriate J-Link to connect to.
So even in IDEs which do not have an selection option for the J-Link, it is possible to connect
to different J-Links.
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6.7
Using the J-Link DLL
Using the J-Link DLL
6.7.1
What is the JLink DLL?
The J-LinkARM.dll is a standard Windows DLL typically used from C or C++, but also Visual
Basic or Delphi projects. It makes the entire functionality of the J-Link / J-Trace available
through the exported functions. The functionality includes things such as halting/stepping
the ARM core, reading/writing CPU and ICE registers and reading/writing memory. Therefore, it can be used in any kind of application accessing a CPU core.
6.7.2
Updating the DLL in third-party programs
The JLink DLL can be used by any debugger that is designed to work with it. Some debuggers
are usually shipped with the J-Link DLL already installed. Anyhow it may make sense to
replace the included DLL with the latest one available, to take advantage of improvements
in the newer version.
6.7.2.1 Updating the J-Link DLL in the IAR Embedded Workbench for
ARM (EWARM)
6.7.3
Determining the version of JLink DLL
To determine which version of the JLinkARM.dll you are using, the DLL version can be viewed
by right clicking the DLL in explorer and choosing Properties from the context menu. Click
the Version tab to display information about the product version.
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6.7.4
Using the J-Link DLL
Determining which DLL is used by a program
To verify that the program you are working with is using the DLL you expect it to use, you
can investigate which DLLs are loaded by your program with tools like Sysinternals’ Process
Explorer. It shows you details about the DLLs used by your program, such as manufacturer
and version.
Process Explorer is - at the time of writing - a free utility which can be downloaded from
www.sysinternals.com .
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Working with J-Link and JTrace
This chapter describes functionality and how to use J-Link and J-Trace.
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7.1
CHAPTER 7
J-Link WiFi setup
J-Link WiFi setup
For J-Link WiFi setup / specifics, please refer to the SEGGER wiki:
https://wiki.segger.com/UM08001#J-Link_WiFi_setup
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Supported IDEs
Supported IDEs
J-Link supports almost all popular IDEs available today. If support for a IDE is lacking, feel
free to get in contact with SEGGER. (see Contact Information )
For a list of supported 3rd-party debuggers and IDEs and documentation on how to get
started with those IDEs and J-Link / J-Trace es well as on how to use the advanced features
of J-Link / J-Trace with any of them, please refer to:
SEGGER Wiki: Getting Started with Various IDEs and
List of supported IDEs
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7.3
Connecting the target system
Connecting the target system
7.3.1
Power-on sequence
In general, J-Link / J-Trace should be powered on before connecting it with the target
device. That means you should first connect J-Link / J-Trace with the host system via USB
and then connect J-Link / J-Trace with the target device via JTAG. Power-on the device after
you connected J-Link / J-Trace to it.
7.3.2
Verifying target device connection
If the USB driver is working properly and your J-Link / J-Trace is connected with the host
system, you may connect J-Link / J-Trace to your target hardware. Then start JLink.exe
which should now display the normal J-Link / J-Trace related information and in addition to
that it should report that it found a JTAG target and the target’s core ID. The screenshot
below shows the output of JLink.exe . As can be seen, it reports a J-Link with one JTAG
device connected.
7.3.3
Problems
If you experience problems with any of the steps described above, read the chapter Support
and FAQs for troubleshooting tips. If you still do not find appropriate help there and your JLink / J-Trace is an original SEGGER product, you can contact SEGGER support via e-mail.
Provide the necessary information about your target processor, board etc. and we will try
to solve your problem. A checklist of the required information together with the contact
information can be found in chapter Support and FAQs as well.
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7.4
Indicators
Indicators
J-Link uses indicators (LEDs) to give the user some information about the current status
of the connected J-Link. All J-Links feature the main indicator. Some newer J-Links such
as the J-Link Pro / Ultra come with additional input/output Indicators. In the following, the
meaning of these indicators will be explained.
7.4.1
Main indicator
For J-Links up to V7, the main indicator is single color (Green). J-Link V8 comes with a bicolor indicator (Green & Red LED), which can show multiple colors: green, red and orange.
7.4.1.1
Single color indicator (J-Link V7 and earlier)
Indicator status
Meaning
GREEN, flashing at 10 Hz Emulator enumerates.
GREEN, flickering
Emulator is in operation. Whenever the emulator is executing a command, the LED is switched off temporarily. Flickering speed depends on target interface speed. At low interface speeds, operations typically take longer and the “OFF”
periods are typically longer than at fast speeds.
GREEN, constant
Emulator has enumerated and is in idle mode.
GREEN, switched off for
10ms once per second
J-Link heart beat. Will be activated after the emulator has
been in idle mode for at least 7 seconds.
GREEN, flashing at 1 Hz
Emulator has a fatal error. This should not normally happen.
7.4.1.2
Bi-color indicator (J-Link V8)
Indicator status
Meaning
GREEN, flashing at 10 Hz Emulator enumerates.
GREEN, flickering
Emulator is in operation. Whenever the emulator is executing a command, the LED is switched off temporarily. Flickering speed depends on target interface speed. At low interface speeds, operations typically take longer and the “OFF”
periods are typically longer than at fast speeds.
GREEN, constant
Emulator has enumerated and is in idle mode.
GREEN, switched off for
10ms once per second
J-Link heart beat. Will be activated after the emulator has
been in idle mode for at least 7 seconds.
ORANGE
Reset is active on target.
RED, flashing at 1 Hz
Emulator has a fatal error. This should not normally happen.
7.4.2
Input indicator
Some newer J-Links such as the J-Link Pro/Ultra come with additional input/output indicators. The input indicator is used to give the user some information about the status of the
target hardware.
7.4.2.1
Bi-color input indicator
Indicator status
Meaning
GREEN
Target voltage could be measured. Target is connected.
ORANGE
Target voltage could be measured. RESET is pulled low (active) on target side.
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Indicator status
Meaning
RESET is pulled low (active) on target side. If no target is
connected, reset will also be active on target side.
RED
7.4.3
Indicators
Output indicator
Some newer J-Links such as the J-Link Pro/Ultra come with additional input/output indicators. The output indicator is used to give the user some information about the emulator-totarget connection.
7.4.3.1
Bi-color output indicator
Indicator status
Meaning
OFF
Target power supply via Pin 19 is not active.
GREEN
Target power supply via Pin 19 is active.
ORANGE
Target power supply via Pin 19 is active. Emulator pulls
RESET low (active).
RED
Emulator pulls RESET low (active).
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7.5
JTAG interface
JTAG interface
By default, only one device is assumed to be in the JTAG scan chain. If you have multiple
devices in the scan chain, you must properly configure it. To do so, you have to specify the
exact position of the CPU that should be addressed. Configuration of the scan is done by
the target application. A target application can be a debugger such as the IAR C-SPY®
debugger, ARM’s AXD using RDI, a flash programming application such as SEGGER’s JFlash, or any other application using J-Link / J-Trace. It is the application’s responsibility
to supply a way to configure the scan chain. Most applications offer a dialog box for this
purpose.
7.5.1
Multiple devices in the scan chain
J-Link / J-Trace can handle multiple devices in the scan chain. This applies to hardware
where multiple chips are connected to the same JTAG connector. As can be seen in the
following figure, the TCK and TMS lines of all JTAG device are connected, while the TDI
and TDO lines form a bus.
Currently, up to 32 devices in the scan chain are supported. One or more of these devices
can be CPU cores; the other devices can be of any other type but need to comply with
the JTAG standard.
7.5.1.1
Configuration
The configuration of the scan chain depends on the application used. Read JTAG interface
for further instructions and configuration examples.
7.5.2
Sample configuration dialog boxes
As explained before, it is the responsibility of the application to allow the user to configure
the scan chain. This is typically done in a dialog box; some sample dialog boxes are shown
below.
SEGGER J-Flash configuration dialog
This dialog box can be found at Options|Project settings.
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JTAG interface
SEGGER J-Link RDI configuration dialog box
This dialog can be found under RDI|Configure for example in IAR Embedded Workbench®.
For detailed information check the IAR Embedded Workbench user guide.
7.5.3
Determining values for scan chain configuration
If only one device is connected to the scan chain, the default configuration can be used. In
other cases, J-Link / J-Trace may succeed in automatically recognizing the devices on the
scan chain, but whether this is possible depends on the devices present on the scan chain.
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JTAG interface
How do I configure the scan chain?
2 values need to be known:
•
•
The position of the target device in the scan chain.
The total number of bits in the instruction registers of the devices before the target
device (IR len).
The position can usually be seen in the schematic; the IR len can be found in the manual
supplied by the manufacturers of the others devices. ARM7/ARM9 have an IR len of four.
Sample configurations
The diagram below shows a scan chain configuration sample with 2 devices connected to
the JTAG port.
Examples
The following table shows a few sample configurations with 1,2 and 3 devices in different
configurations.
Device 0
Chip(IR len)
Device 1
Chip(IR len)
Device 2
Chip(IR len)
Position
IR len
ARM(4)
-
-
0
0
ARM(4)
Xilinx(8)
-
0
0
Xilinx(8)
ARM(4)
-
1
8
Xilinx(8)
Xilinx(8)
ARM(4)
2
16
ARM(4)
Xilinx(8)
ARM(4)
0
0
ARM(4)
Xilinx(8)
ARM(4)
2
12
Xilinx(8)
ARM(4)
Xilinx(8)
1
8
The target device is marked in blue.
7.5.4
JTAG Speed
There are basically three types of speed settings:
•
Fixed JTAG speed.
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•
•
7.5.4.1
JTAG interface
Automatic JTAG speed.
Adaptive clocking. These are explained below.
Fixed JTAG speed
The target is clocked at a fixed clock speed. The maximum JTAG speed the target can
handle depends on the target itself. In general CPU cores without JTAG synchronization logic
(such as ARM7-TDMI) can handle JTAG speeds up to the CPU speed, ARM cores with JTAG
synchronization logic (such as ARM7-TDMI-S, ARM946E-S, ARM966EJ-S) can handle JTAG
speeds up to 1/6 of the CPU speed. JTAG speeds of more than 10 MHz are not recommended.
7.5.4.2
Automatic JTAG speed
Selects the maximum JTAG speed handled by the TAP controller.
Note
On ARM cores without synchronization logic, this may not work reliably, because the
CPU core may be clocked slower than the maximum JTAG speed.
7.5.4.3
Adaptive clocking
If the target provides the RTCK signal, select the adaptive clocking function to synchronize
the clock to the processor clock outside the core. This ensures there are no synchronization
problems over the JTAG interface. If you use the adaptive clocking feature, transmission
delays, gate delays, and synchronization requirements result in a lower maximum clock
frequency than with non-adaptive clocking.
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7.6
SWD interface
SWD interface
The J-Link support ARMs Serial Wire Debug (SWD). SWD replaces the 5-pin JTAG port with a
clock (SWDCLK) and a single bi-directional data pin (SWDIO), providing all the normal JTAG
debug and test functionality. SWDIO and SWCLK are overlaid on the TMS and TCK pins. In
order to communicate with a SWD device, J-Link sends out data on SWDIO, synchronous
to the SWCLK. With every rising edge of SWCLK, one bit of data is transmitted or received
on the SWDIO.
7.6.1
SWD speed
Currently only fixed SWD speed is supported by J-Link. The target is clocked at a fixed
clock speed. The SWD speed which is used for target communication should not exceed
target CPU speed * 10 . The maximum SWD speed which is supported by J-Link depends on
the hardware version and model of J-Link. For more information about the maximum SWD
speed for each J-Link / J-Trace model, please refer to J-Link / J-Trace models on page 35.
7.6.2
SWO
Serial Wire Output (SWO) support means support for a single pin output signal from the
core. The Instrumentation Trace Macrocell (ITM) and Serial Wire Output (SWO) can be used
to form a Serial Wire Viewer (SWV). The Serial Wire Viewer provides a low cost method of
obtaining information from inside the MCU. Usually it should not be necessary to configure
the SWO speed because this is usually done by the debugger.
7.6.2.1
Max. SWO speeds
The supported SWO speeds depend on the connected emulator. They can be retrieved from
the emulator. To get the supported SWO speeds for your emulator, use J-Link Commander:
J-Link> si 1 //Select target interface SWD
J-Link> SWOSpeed
Currently, following speeds are supported:
Emulator
Speed formula
Resulting max. speed
J-Link V9
60MHz/n, n ≥ 8
7.5 MHz
J-Link Pro/ULTRA V4
3.2GHz/n, n ≥ 64
50 MHz
7.6.2.2
Configuring SWO speeds
The max. SWO speed in practice is the max. speed which both, target and J-Link can
handle. J-Link can handle the frequencies described in SWO whereas the max. deviation
between the target and the J-Link speed is about 3%. The computation of possible SWO
speeds is typically done in the debugger. The SWO output speed of the CPU is determined
by TRACECLKIN, which is normally the same as the CPU clock.
Example 1
Target CPU running at 72 MHz. n is between 1 and 8192.
Possible SWO output speeds are:
72MHz, 36MHz, 24MHz, ...
J-Link V9: Supported SWO input speeds are: 60MHz / n, n>= 8:
7.5MHz, 6.66MHz, 6MHz, ...
Permitted combinations are:
SWO output
6MHz, n = 12
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SWO input
6MHz, n = 10
Deviation percent
0
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SWO output
SWO input
SWD interface
Deviation percent
4MHz, n = 18
4MHz, n = 15
0
…
…
≤3
2MHz, n = 36
2MHz, n = 30
0
…
…
…
TEXT
TEXT
TEXT
TEXT
TEXT
TEXT
TEXT
TEXT
TEXT
TEXT
TEXT
TEXT
Example 2
Target CPU running at 10 MHz.
Possible SWO output speeds are:
10MHz, 5MHz, 3.33MHz, ...
J-Link V7: Supported SWO input speeds are: 6MHz / n, n>= 1:
6MHz, 3MHz, 2MHz, 1.5MHz, ...
Permitted combinations are:
SWO output
SWO input
Deviation percent
2MHz, n = 5
2MHz, n = 3
0
1MHz, n = 10
1MHz, n = 6
0
769kHz, n = 13
750kHz, n = 8
2.53
…
…
…
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7.7
Multi-core debugging
Multi-core debugging
J-Link / J-Trace is able to debug multiple cores on one target system connected to the same
scan chain. Configuring and using this feature is described in this section.
7.7.1
How multi-core debugging works
Multi-core debugging requires multiple debuggers or multiple instances of the same debugger. Two or more debuggers can use the same J-Link / J-Trace simultaneously. Configuring
a debugger to work with a core in a multi-core environment does not require special settings. All that is required is proper setup of the scan chain for each debugger. This enables
J-Link / J-Trace to debug more than one core on a target at the same time. The following
figure shows a host, debugging two CPU cores with two instances of the same debugger.
Both debuggers share the same physical connection. The core to debug is selected through
the JTAG-settings as described below.
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7.7.2
Multi-core debugging
Using multi-core debugging in detail
1. Connect your target to J-Link / J-Trace.
2. Start your debugger, for example IAR Embedded Workbench for ARM.
3. Choose Project|Options and configure your scan chain. The picture below shows the
configuration for the first CPU core on your target.
4. Start debugging the first core.
5. Start another debugger, for example another instance of IAR Embedded Workbench for
ARM.
6. Choose Project|Options and configure your second scan chain. The following dialog box
shows the configuration for the second ARM core on your target.
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Multi-core debugging
7. Start debugging your second core.
Core #1
Core #2
TAP number
debugger #1
Core #3
TAP number
debugger #2
ARM7TDMI
ARM7TDMI-S
ARM7TDMI
0
1
ARM7TDMI
ARM7TDMI
ARM7TDMI
0
2
ARM7TDMI-S
ARM7TDMI-S
ARM7TDMI-S
1
2
7.7.3
Things you should be aware of
Multi-core debugging is more difficult than single-core debugging. You should be aware of
the pitfalls related to JTAG speed and resetting the target.
7.7.3.1
JTAG speed
Each core has its own maximum JTAG speed. The maximum JTAG speed of all cores in the
same chain is the minimum of the maximum JTAG speeds. For example:
•
•
•
7.7.3.2
Core #1: 2MHz maximum JTAG speed
Core #2: 4MHz maximum JTAG speed
Scan chain: 2MHz maximum JTAG speed
Resetting the target
All cores share the same RESET line. You should be aware that resetting one core through
the RESET line means resetting all cores which have their RESET pins connected to the
RESET line on the target.
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7.8
Connecting multiple J-Links / J-Traces to your PC
Connecting multiple J-Links / J-Traces to your PC
In general, it is possible to have an unlimited number of J-Links / J-Traces connected to the
same PC. Current J-Link models are already factory-configured to be used in a multi-J-Link
environment, older J-Links can be re-configured to use them in a multi-J-link environment.
7.8.1
How does it work?
USB devices are identified by the OS by their product ID, vendor id and serial number.
The serial number reported by current J-Links is a unique number which allows to have
an almost unlimited number of J-Links connected to the same host at the same time. In
order to connect to the correct J-Link, the user has to make sure that the correct J-Link is
selected (by SN or IP). In cases where no specific J-Link is selected, following pop up will
shop and allow the user to select the proper J-Link:
The sketch below shows a host, running two application programs. Each application communicates with one CPU core via a separate J-Link.
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Connecting multiple J-Links / J-Traces to your PC
Older J-Links may report USB0-3 instead of unique serial number when enumerating via
USB. For these J-Links, we recommend to re-configure them to use the new enumeration
method (report real serial number) since the USB0-3 behavior is obsolete.
Re-configuration can be done by using the J-Link Configurator, which is part of the J-Link
Software and Documentation Package. For further information about the J-Link Configurator
and how to use it, please refer to J-Link Configurator .
Re-configuration to the old USB 0-3 enumeration method
In some special cases, it may be necessary to switch back to the obsolete USB 0-3 enumeration method. For example, old IAR EWARM versions supports connecting to a J-Link
via the USB0-3 method only. As soon as more than one J-Link is connected to the pc, there
is no opportunity to pre-select the J-Link which should be used for a debug session.
Below, a small instruction of how to re-configure J-Link to enumerate with the old obsolete
enumeration method in order to prevent compatibility problems, a short instruction is give
on how to set USB enumeration method to USB 2 is given:
Config area byte
Meaning
0
USB-Address. Can be set to 0-3, 0xFF is default which
means USB-Address 0.
1
Enumeration method
0x00 / 0xFF: USB-Address is used for enumeration.
0x01: Real-SN is used for enumeration.
Example for setting enumeration method to USB 2:
1.
2.
3.
4.
Start J-Link Commander (JLink.exe) which is part of the J-Link software
Enter wconf 0 02 // Set USB-Address 2
Enter wconf 1 00 // Set enumeration method to USB-Address
Power-cycle J-Link in order to apply new configuration. Re-configuration to REAL-SN
enumeration can be done by using the J-Link Configurator, which is part of the JLink Software and Documentation Package. For further information about the J-Link
Configurator and how to use it, please refer to J-Link Configurator .
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7.9
J-Link control panel
J-Link control panel
Since software version V3.86 J-Link the J-Link control panel window allows the user to
monitor the J-Link status and the target status information in real-time. It also allows the
user to configure the use of some J-Link features such as flash download, flash breakpoints
and instruction set simulation. The J-Link control panel window can be accessed via the JLink tray icon in the tray icon list. This icon is available when the debug session is started.
To open the status window, simply click on the tray icon.
7.9.1
Tabs
The J-Link status window supports different features which are grouped in tabs. The organization of each tab and the functionality which is behind these groups will be explained
in this section
7.9.1.1
General
In the General section, general information about J-Link and the target hardware are shown.
Moreover the following general settings can be configured:
•
•
•
Show tray icon: If this checkbox is disabled the tray icon will not show from the next
time the DLL is loaded.
Start minimized: If this checkbox is disabled the J-Link status window will show up
automatically each time the DLL is loaded.
Always on top: If this checkbox is enabled the J-Link status window is always visible
even if other windows will be opened.
The general information about target hardware and J-Link which are shown in this section,
are:
•
•
•
•
•
•
•
Process: Shows the path of the file which loaded the DLL.
J-Link: Shows OEM of the connected J-Link, the hardware version and the Serial number.
If no J-Link is connected it shows “not connected” and the color indicator is red.
Target interface: Shows the selected target interface (JTAG/SWD) and the current JTAG
speed. The target current is also shown. (Only visible if J-Link is connected)
Endian: Shows the target endianness (Only visible if J-Link is connected)
Device: Shows the selected device for the current debug session.
License: Opens the J-Link license manager.
About: Opens the about dialog.
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7.9.1.2
J-Link control panel
Settings
In the Settings section project- and debug-specific settings can be set. It allows the configuration of the use of flash download and flash breakpoints and some other target specific
settings which will be explained in this topic. Settings are saved in the configuration file.
This configuration file needs to be set by the debugger. If the debugger does not set it, settings can not be saved. All settings which are modified during the debug session have to be
saved by pressing Save settings, otherwise they are lost when the debug session is closed.
Section: Flash download
In this section, settings for the use of the J-Link FlashDL feature and related settings can
be configured. When a license for J-Link FlashDL is found, the color indicator is green and
“License found” appears right to the J-Link FlashDL usage settings.
•
•
•
•
•
Auto: This is the default setting of J-Link FlashDL usage. If a license is found J-Link
FlashDL is enabled. Otherwise J-Link FlashDL will be disabled internally.
On: Enables the J-Link FlashDL feature. If no license has been found an error message
appears.
Off: Disables the J-Link FlashDL feature.
Skip download on CRC match: J-Link checks the CRC of the flash content to determine if
the current application has already been downloaded to the flash. If a CRC match occurs,
the flash download is not necessary and skipped. (Only available if J-Link FlashDL usage
is configured as Auto or On )
Verify download: If this checkbox is enabled J-Link verifies the flash content after the
download. (Only available if J-Link FlashDL usage is configured as Auto or On )
Section: Flash breakpoints:
In this section, settings for the use of the FlashBP feature and related settings can be
configured. When a license for FlashBP is found, the color indicator is green and “License
found” appears right to the FlashBP usage settings.
•
•
•
•
Auto: This is the default setting of FlashBP usage. If a license has been found the FlashBP
feature will be enabled. Otherwise FlashBP will be disabled internally.
On: Enables the FlashBP feature. If no license has been found an error message appears.
Off: Disables the FlashBP feature.
Show window during program : When this checkbox is enabled the “Programming flash”
window is shown when flash is re-programmed in order to set/clear flash breakpoints.
Flash download and flash breakpoints independent settings
These settings do not belong to the J-Link flash download and flash breakpoints settings
section. They can be configured without any license needed.
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•
•
•
•
•
•
•
7.9.1.3
J-Link control panel
Log file: Shows the path where the J-Link log file is placed. It is possible to override
the selection manually by enabling the Override checkbox. If the Override checkbox is
enabled a button appears which let the user choose the new location of the log file.
Settings file: Shows the path where the configuration file is placed. This configuration
file contains all the settings which can be configured in the Settings tab.
Override device selection: If this checkbox is enabled, a dropdown list appears, which
allows the user to set a device manually. This especially makes sense when J-Link can
not identify the device name given by the debugger or if a particular device is not yet
known to the debugger, but to the J-Link software.
Allow caching of flash contents : If this checkbox is enabled, the flash contents are
cached by J-Link to avoid reading data twice. This speeds up the transfer between
debugger and target.
Allow instruction set simulation: If this checkbox is enabled, instructions will be
simulated as far as possible. This speeds up single stepping, especially when FlashBPs
are used.
Save settings: When this button is pushed, the current settings in the Settings tab will
be saved in a configuration file. This file is created by J-Link and will be created for each
project and each project configuration (e.g. Debug_RAM, Debug_Flash). If no settings
file is given, this button is not visible.
Modify breakpoints during execution: This dropdown box allows the user to change
the behavior of the DLL when setting breakpoints if the CPU is running. The following
options are available:
Allow: Allows settings breakpoints while the CPU is running. If the CPU needs to be
halted in order to set the breakpoint, the DLL halts the CPU, sets the breakpoints and
restarts the CPU.
Allow if CPU does not need to be halted: Allows setting breakpoints while the CPU is
running, if it does not need to be halted in order to set the breakpoint. If the CPU has
to be halted the breakpoint is not set.
Ask user if CPU needs to be halted: If the user tries to set a breakpoint while the CPU
is running and the CPU needs to be halted in order to set the breakpoint, the user is
asked if the breakpoint should be set. If the breakpoint can be set without halting the
CPU, the breakpoint is set without explicit confirmation by the user.
Do not allow: It is not allowed to set breakpoints while the CPU is running.
Break/Watch
In the Break/Watch section all breakpoints and watchpoints which are in the DLL internal
breakpoint and watchpoint list are shown.
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J-Link control panel
Section: Code
Lists all breakpoints which are in the DLL internal breakpoint list are shown.
•
•
•
•
•
Handle: Shows the handle of the breakpoint.
Address: Shows the address where the breakpoint is set.
Mode: Describes the breakpoint type (ARM/THUMB)
Permission: Describes the breakpoint implementation flags.
Implementation: Describes the breakpoint implementation type. The breakpoint types
are: RAM, Flash, Hard. An additional TBC (to be cleared) or TBS (to be set) gives
information about if the breakpoint is (still) written to the target or if it’s just in the
breakpoint list to be written/cleared.
Note
It is possible for the debugger to bypass the breakpoint functionality of the J-Link software by writing to the debug registers directly. This means for ARM7/ARM9 cores write
accesses to the ICE registers, for Cortex-M3 devices write accesses to the memory
mapped flash breakpoint registers and in general simple write accesses for software
breakpoints (if the program is located in RAM). In these cases, the J-Link software
cannot determine the breakpoints set and the list is empty.
Section: Data
In this section, all data breakpoints which are listed in the DLL internal breakpoint list are
shown.
•
•
•
•
•
•
•
7.9.1.4
Handle: Shows the handle of the data breakpoint.
Address: Shows the address where the data breakpoint is set.
AddrMask: Specifies which bits of Address are disregarded during the comparison for a
data breakpoint match. (A 1 in the mask means: disregard this bit)
Data: Shows on which data to be monitored at the address where the data breakpoint
is set.
Data Mask: Specifies which bits of Data are disregarded during the comparison for a
data breakpoint match. (A 1 in the mask means: disregard this bit)
Ctrl: Specifies the access type of the data breakpoint (read/write).
CtrlMask: Specifies which bits of Ctrl are disregarded during the comparison for a data
breakpoint match.
Log
In this section the log output of the DLL is shown. The user can determine which function
calls should be shown in the log window. Available function calls to log: Register read/write,
Memory read/write, set/clear breakpoint, step, go, halt, is halted.
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7.9.1.5
J-Link control panel
CPU Regs
In this section the name and the value of the CPU registers are shown.
7.9.1.6
Target Power
In this section currently just the power consumption of the target hardware is shown.
7.9.1.7
SWV
In this section SWV information are shown.
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•
•
•
•
•
•
J-Link control panel
Status: Shows the encoding and the baudrate of the SWV data received by the target
(Manchester/UART, currently J-Link only supports UART encoding).
Bytes in buffer: Shows how many bytes are in the DLL SWV data buffer.
Bytes transferred: Shows how many bytes have been transferred via SWV, since the
debug session has been started.
Refresh counter: Shows how often the SWV information in this section has been updated
since the debug session has been started.
Host buffer: Shows the reserved buffer size for SWV data, on the host side.
Emulator buffer: Shows the reserved buffer size for SWV data, on the emulator side.
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7.10
Reset strategies
Reset strategies
Wiki article J-Link Reset Strategies
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7.11
Using DCC for memory access
Using DCC for memory access
The ARM7/9 architecture requires cooperation of the CPU to access memory when the CPU is
running (not in debug mode). This means that memory cannot normally be accessed while
the CPU is executing the application program. The normal way to read or write memory
is to halt the CPU (put it into debug mode) before accessing memory. Even if the CPU is
restarted after the memory access, the real time behavior is significantly affected; halting
and restarting the CPU costs typically multiple milliseconds. For this reason, most debuggers
do not even allow memory access if the CPU is running.
However, there is one other option: DCC (Direct communication channel) can be used to
communicate with the CPU while it is executing the application program. All that is required
is the application program to call a DCC handler from time to time. This DCC handler
typically requires less than 1 s per call.
The DCC handler, as well as the optional DCC abort handler, is part of the J-Link software
package and can be found in the Samples\DCC\IAR directory of the package.
7.11.1
•
•
•
What is required?
An application program on the host (typically a debugger) that uses DCC.
A target application program that regularly calls the DCC handler.
The supplied abort handler should be installed (optional).
An application program that uses DCC is JLink.exe .
7.11.2
Target DCC handler
The target DCC handler is a simple C-file taking care of the communication. The function
DCC_Process() needs to be called regularly from the application program or from an interrupt handler. If an RTOS is used, a good place to call the DCC handler is from the timer tick
interrupt. In general, the more often the DCC handler is called, the faster memory can be
accessed. On most devices, it is also possible to let the DCC generate an interrupt which
can be used to call the DCC handler.
7.11.3
Target DCC abort handler
An optional DCC abort handler (a simple assembly file) can be included in the application.
The DCC abort handler allows data aborts caused by memory reads/writes via DCC to be
handled gracefully. If the data abort has been caused by the DCC communication, it returns
to the instruction right after the one causing the abort, allowing the application program to
continue to run. In addition to that, it allows the host to detect if a data abort occurred.
In order to use the DCC abort handler, 3 things need to be done:
•
•
•
Place a branch to DCC_Abort at address 0x10 (“vector” used for data aborts).
Initialize the Abort-mode stack pointer to an area of at least 8 bytes of stack memory
required by the handler.
Add the DCC abort handler assembly file to the application.
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7.12
The J-Link settings file
The J-Link settings file
Most IDEs provide a path to a J-Link settings file on a per-project-per-debug-configuration
basis. This file is used by J-Link to store various debug settings that shall survive between
debug sessions of a project. It also allows the user to perform some override of various
settings. If a specific behavior / setting can be overridden via the settings file, is explained
in the specific sections that describe the behavior / setting. Since the location and name
of the settings file is different for various IDEs, in the following the location and naming
convention of the J-Link settings file for various IDEs is explained.
7.12.1
SEGGER Embedded Studio
Settings file with default settings is created on first start of a debug session. There is one
settings file per build configuration for the project.
Naming is: __.jlink
The settings file is created in the same directory where the project file (*.emProject) is
located.
Example: The SES project is called “MyProject” and has two configurations “Debug” and
“Release”. For each of the configurations, a settings file will be created at the first start
of the debug session:
_MyProject_Debug.jlink _MyProject_Release.jlink
7.12.2
Keil MDK-ARM (uVision)
Settings file with default settings is created on first start of a debug session. There is one
settings file per project.
Naming is: JLinksettings.ini
The settings file is created in the same directory where the project file (*.uvprojx) is located.
7.12.3
IAR EWARM
Settings file with default settings is created on first start of a debug session. There is one
settings file per build configuration for the project.
Naming is: _.jlink
The settings file is created in a “settings” subdirectory where the project file is located.
7.12.4
Mentor Sourcery CodeBench for ARM
CodeBench does not directly specify a J-Link settings file but allows the user to specify
a path to one in the project settings under Debugger -> Settings File . We recommend
to copy the J-Link settings file template from $JLINK_INST_DIR$\Samples\JLink\SettingsFiles\Sample.jlinksettings to the directory where the CodeBench project is located, once
when creating a new project. Then select this file in the project options.
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7.13
J-Link script files
J-Link script files
In some situations it it necessary to customize some actions performed by J-Link. In most
cases it is the connection sequence and/or the way in which a reset is performed by J-Link,
since some custom hardware needs some special handling which cannot be integrated into
the generic part of the J-Link software. J-Link script files are written in C-like syntax in
order to have an easy start to learning how to write J-Link script files. The script file syntax
supports most statements (if-else, while, declaration of variables, …) which are allowed in
C, but not all of them. Moreover, there are some statements that are script file specific. The
script file allows maximum flexibility, so almost any target initialization which is necessary
can be supported.
7.13.1
Actions that can be customized
The script file support allows customizing of different actions performed by J-Link. Depending on whether the corresponding function is present in the script file or not, a generically
implemented action is replaced by an action defined in a script file. In the following all JLink actions which can be customized using a script file are listed and explained.
Action
Prototype
ConfigTargetSettings()
int ConfigTargetSettings (void);
InitTarget()
int InitTarget (void);
SetupTarget()
int SetupTarget (void);
ResetTarget()
int ResetTarget (void);
InitEmu()
int InitEMU (void);
OnTraceStop()
int OnTraceStop (void);
OnTraceStart()
int OnTraceStart (void);
AfterResetTarget()
int AfterResetTarget (void);
SWO_EnableTarget()
int SWO_EnableTarget (void);
SWO_GetSWOBaseClock()
U32 SWO_GetSWOBaseClock (U32 CPUclock);
HandleBeforeFlashProg()
int HandleBeforeFlashProg (void);
HandleAfterFlashProg()
int HandleAfterFlashProg (void);
StartETM()
int StartETM (void);
StopETM()
int StopETM (void);
StartTPIU()
int StartTPIU (void);
StopTPIU()
int StopTPIU (void);
StartTMC()
int StartTMC (void);
StopTMC()
int StopTMC (void);
StartPTM()
int StartPTM (void);
StopPTM()
int StopPTM (void);
StartTF()
int StartTF (void);
StopTF()
int StopTF (void);
StartETB()
int StartETB (void);
StopETB()
int StopETB (void);
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J-Link script files
Note
The default return values for all listed functions above are:
Return value
7.13.1.1
Meaning
≥0
O.K.
ICEPick (6-bits IRLen) -> Cortex-M (4-bits IRLen) -> TDO
JLINK_CORESIGHT_Configure("IRPre=0;DRPre=0;IRPost=6;DRPost=1;IRLenDevice=4;");
v = JLINK_CORESIGHT_ReadDP(JLINK_CORESIGHT_DP_REG_CTRL_STAT);
JLINK_SYS_Report1("DAP-CtrlStat: " v)
Known setup parameters
Parameter
Type
Explanation
IRPre
DecValue
Sum of IRLen of all JTAG devices in the JTAG chain, closer
to TDO than the actual one J-Link shall communicate with.
DRPre
DecValue
Number of JTAG devices in the JTAG chain, closer to TDO
than the actual one, J-Link shall communicate with.
IRPost
DecValue
Sum of IRLen of all JTAG devices in the JTAG chain, following the actual one, J-Link shall communicate with.
DRPost
DecValue
Number of JTAG devices in the JTAG chain, following the actual one, J-Link shall communicate with.
IRLenDevice
DecValue
IRLen of the actual device, J-Link shall communicate with.
PerformTIFInit DecValue
J-Link / J-Trace (UM08001)
0: Do not output switching sequence etc. once
JLINK_CORESIGHT_Configure() completes.
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7.13.2.7
J-Link script files
JLINK_CORESIGHT_ReadAP()
Reads a specific AP register. For JTAG, makes sure that AP is selected automatically. Makes
sure that actual data is returned, meaning for register read-accesses which usually only
return data on the second access, this function performs this automatically, so the user
will always see valid data.
Prototype
int JLINK_CORESIGHT_ReadAP(int RegIndex);
Parameter
RegIndex
Return
value
Description
Specifies the index of the AP register to read.
Description
≠ -1
Data read
= -1
Error
Example
v = JLINK_CORESIGHT_ReadAP(JLINK_CORESIGHT_AP_REG_DATA);
JLINK_SYS_Report1("DATA: " v);
7.13.2.8
JLINK_CORESIGHT_ReadDP()
Reads a specific DP register. For JTAG, makes sure that DP is selected automatically. Makes
sure that actual data is returned, meaning for register read-accesses which usually only
return data on the second access, this function performs this automatically, so the user
will always see valid data.
Prototype
int JLINK_CORESIGHT_ReadDP(int RegIndex);
Parameter
RegIndex
Return
value
Description
Specifies the index of the DP register to read.
Description
≠ -1
Data read
= -1
Error
Example
v = JLINK_CORESIGHT_ReadDP(JLINK_CORESIGHT_DP_REG_IDCODE);
JLINK_SYS_Report1("DAP-IDCODE: " v);
7.13.2.9
JLINK_CORESIGHT_ReadDAP()
Reads a specific AP/DP register. For JTAG, makes sure that AP/DP is selected automatically.
Makes sure that actual data is returned, meaning for register read-accesses which usually
only return data on the second access, this function performs this automatically, so the
user will always see valid data.
Prototype
int JLINK_CORESIGHT_ReadDAP(int RegIndex, int APnDP, U32* Data);
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Parameter
J-Link script files
Description
RegIndex
Specifies the index of the AP/DP register to read.
APnDP
0: DP register
1: AP register
Data
Pointer to buffer for data read
Return Value
Return
value
Description
≥0
O.K. (Number of repetitions needed before read was accepted / returned valid
data)
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