The RAM code then communicates with the host computer (via DCC, JTAG and J-Link / J-Trace), transferring data to the target. Cross-platform support - Runs on Windows, Linux, Mac OS X. on the 19 pin connector pin 11 and 13 This monitor code performs the communication with J-Link while the CPU is in debug mode (meaning in the monitor exception). The J-Link flash download feature can be used by different debuggers, such as IAR Embedded Workbench, Keil MDK, GDB based IDEs, . There are three options for the trace signal termination: Where available, the best termination scheme is to have the CPU manufacturer match the output impedance of the driver to the impedance of the PCB track on your board. For information about trace support of a target device, please refer to the device's User/Reference Manual. When the breakpoint is hit, the debugger can recreate the instruction flow, based on the trace data provided by J-Trace, For this reason, most debuggers do not even allow memory access if the CPU is running. There are two common approaches how a trace probe collects trace data: Code coverage metrics are a way to describe the "quality" of code, as it shows how much code was executed while running in a test setup. Serial Wire Output (SWO) overview J-Link can be used with devices that supports Serial Wire Output (SWO). Fax: +1-978-874-0599, Silicon Valley This also implies that the execution address must be the same as the download address. The screenshot below shows an example output when connecting to the SEGGER Cortex-M Trace Reference Board: If you experience problems with any of the steps described above, please refer to the J-Link troubleshooting guide. To do so, the exact position of the CPU that should be addressed has to be specified. The setup and behavior is the same as if download into internal flash, which mainly means the device has to be selected and nothing else, would be performed. After changing the configuration a power on cycle of the debug probe is necessary in order to use the new configuration. Out dated firmware might not execute properly with newer hardware versions. A write buffer and a D-Cache configured in write-back mode can further complicate the problem. As useful this is for the application, as problematic it is for debugging. In general CPU cores without JTAG synchronization logic (such as ARM7-TDMI) can handle JTAG speeds up to the CPU speed, To get the supported SWO speeds for your emulator, use J-Link Commander: A list of the available probes and the corresponding max. 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. In order to use the DCC abort handler, 3 things need to be done: The J-Link setting file is only relevant for IDE developers and thus not further discussed here anymore. where the PCB is designed to support both functions with differing tracking requirements. List of supported IDEs. The monitor code needs to be compiled and linked as a normal part of the application. It is normally fed from VDD of the target board and must not have a series resistor. 1 ns ts and min. Some newer, high end J-Links such as the J-Link Pro/Ultra come with additional input/output indicators. This could be for example. that only the affected device is selected and all other ones enter a listening state where they do not respond on the bus anymore but Configuration of the scan is done by the application using J-Link / J-Trace. flash loader if the debugger writes to a specific memory address. No additional setup is required. ARM that provides the ETM as a trace component for their cores). Because ARM7 cores have a unified cache, there is no need to handle the caches during debug. Command line version of the J-Link GDB Server. (Info about about J-Link Commander and Segger RTT is also given.) Please make sure that Windows Defender virus definitions are up to date when downloading the package and are at least at the following version: For example, do not run dynamic signals parallel to each other for any significant distance, keep them spaced well apart, and use a ground plane and so forth. The sectorization command set and other flash parameters are fully auto-detected by the J-Link DLL, so no special user setup is required. This firmware update is performed automatically as necessary by the J-Link DLL. Or any other suggestion? This enables a fast and efficient way to improve the code or to create a suitable test suite for uncovered blocks. It's a variable font in 32 styles that allows you to create any combination and form. The Serial Wire Viewer provides a low-cost method of obtaining information from inside the MCU. ), Synthesizable cores (ARM7TDMI-S, ARM9E-S, etc. If the probe does not support CMSIS-DAP, then there is no such Boot mode option. The output indicator is used to give the user some information about the emulator-to-target connection. Additional information about the targit is shown (e.g. The header exposes a ground pin, a +3.3V pin, a clock pin, and a data pin. However, there are cases where the application, downloaded at debug session start, may change during debugging it. The flash memory can be the internal flash memory of a supported microcontroller or external CFI-compliant flash memory. Manipulation of the stackpointer register (SP) from within the IDE is not possible as the stackpointer is necessary for resuming the user application on Go(). With every rising edge of SWCLK, one bit of data is transmitted or received on the SWDIO. SWD and SWO (also called SWV) Compatibility 3. cJTAG Compatibility JTAG Interface Connection (20 pin) A lot of debuggers (some of them integrated into an IDE) come with their own flash loaders (e.g. This DCC handler typically requires less than 1 s per call. Can be used in parallel with a debugger or stand-alone. For such cases, it is impossible for J-Link to automatically check for the existence of a monitor mode handler as the handler is usually linked in the user application and Two values are required to setup the chain: The position can usually be found in the schematics; the IR length can be found in the manual supplied by the manufacturers of the others devices. current is 300mA. For more information about licensing itself and which devices have a device-based license, please refer to The J-Link model overview. Particular attention must be paid to the TRACECLK signal. There are basically 2 types of breakpoints in a computer system: Hardware breakpoints and software breakpoints. The J-Link / J-Trace has to be updated to the desired firmware. For example, ARM7/ARM9 have an IR length of four. The max. SEGGER can neither offer support for those nor guarantee that The output current is monitored and protected against overload and short-circuit. Code profiling is a form of measuring the execution time and the execution count of functions, blocks or instructions. These keys are located in the registry path HKEY_CURRENT_USER -> Software -> SEGGER -> J-Link. Pinouts of various JTAG interfaces, shown on 0.1" shrouded male headers in this case. There are certain signal timings that must be met, such as rise/fall timings for clock and data, as well as setup and hold timings for the trace data. Series (source) termination is the most commonly used method. If not otherwise mentioned, the following models are affected by these safety notes: Before contacting support, make sure you tried to solve the problem by following the steps outlined in the J-Link troubleshooting guide. Start the J-Link Commander (JLink.exe) which should now display the normal J-Link / J-Trace related information. Not all devices that support SWD also support multi-drop. Operating temperature +5C +60C (+5C +45C for, Relative humidity (non-condensing) Max. (depending on the IDE integration and the behavior of the IDE, reaction time can be 2-3 times faster with caching certain contents). The following cases are the most common ones: While cases 1-3 are the most convenient ones from the debug perspective because the low power mode is transparent to the end user, when the trace pins are needed as GPIOs etc. on how to use the advanced features of J-Link / J-Trace with any of them, please refer to: In other words, the hardware dictates how many hardware breakpoints can be set simultaneously. Adapts from 20-pin, 0.1 inch J-Link connector to 6-pin, 0.05 inch needle pattern. The J-Link and J-Trace support cJTAG for ARM and RISC-V. cJTAG (IEEE 1149.7) is an extension to the JTAG standard (IEEE 1149.1), that reduces the number of required pins by multiplexing the TMS, TDI and TDO signals on a single bi-directional pin, providing all the normal JTAG debug and test functionality. ARM 7/9 cores have 2 breakpoint units (called "watchpoint units" in ARM's documentation), allowing 2 hardware breakpoints to be set. Two or more debuggers can use the same J-Link / J-Trace simultaneously. With this information it is possible to detect code which has not been covered by tests or may even be unreachable. Hardware breakpoints require a dedicated hardware unit for every breakpoint. few ms for at least a few us. 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. Often, more than one breakpoint is located in the same flash sector, which allows programming multiple breakpoints by programming just a single sector. This is the most common streaming tracing method. Serious consideration must be given to high-speed signals when designing the target system. The maximum SWD speed which is supported by J-Link depends on the hardware version and model of J-Link. DRLen of the device to connect to). (Q)SPI flashes, that are not supported by the J-Link DLL can be added manually, with the Open Flashloader. Single color indicator (J-Link V7 and earlier), Determining values for scan chain configuration, Connecting multiple J-Links / J-Traces to your PC, Reconfiguration of older J-Link models to the new enumeration method, Re-configuration to the old USB 0-3 enumeration method, Non-synthesizable cores (ARM7TDMI, ARM9TDMI, ARM920, etc. 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. For example, in case the target CPU does not provide a (sufficient) trace data setup time, the data sample timing can be adjusted inside J-Trace. Only interrupts with a lower priority than the debug/monitor interrupt can be debugged / stepped. 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 the VTref signal should not be wired to save one more pin / place on the target hardware interface connector (e.g. In this case, the RAM code is started as described above before downloading any data. For Cortex-M3 and Cortex-M4, monitor mode debugging is supported. It also comes with USB-drivers for J-Link, J-Trace and Flasher. J-Link automatically restores the monitor bits within a few microseconds, after they have been detected as being cleared without explicitly being cleared by J-Link. Designed by: Dmitry Rastvortsev. Connect to the J-Link / J-Trace you want to replace the firmware on. If the device may also be accessed via JTAG, this pin may be connected to TDI, otherwise leave open. or are not available on all packages of the device). In case both addresses differ from each other, the J-Link software needs to be told that the unknown addresses hold the same data as the cached ones. 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 The J-Link Software and Documentation Pack, available for download on the SEGGER homepage, includes applications to be used with J-Link and J-Trace and in some cases Flasher. Note:These principles apply to all of the trace port signals (TRACECLK, TRACEDATA[0], TRACEDATA[1], TRACEDATA[2], TRACEDATA[3]). J-Flash is a stand-alone Windows application, which can read / write data files and program the flash in almost any ARM system. A few debuggers come with their own flashloaders and need to be configured to use the J-Link flashloader in order to achieve the maximum possible performance. current is 300mA. There are usually 4 trace data pins on which data is output, resulting in 1 byte trace data being output per trace clock (2 * 4 bits). This means that memory cannot normally be accessed while the CPU is executing the application program. This pin is not used by J-Link when operating in SWD mode. For more information about the different adapters, please refer to the SEGGER website. Software breakpoints are different: The debugger modifies the program and replaces the breakpointed instruction with a special value. Note: This allows the user to use J-Link with any RDI-compliant debugger. In this case, the CPU will stop at the first instruction in the ISR (typically at address 0x18). This process usually takes less than 3 seconds and does not require power cycle of the J-Link. and provides these events to the trace probe. Configuring a debugger to work with a core in a multi-core environment does not require special settings. It is the application's responsibility to supply a way to configure the scan chain. Therefore, switching off CPU clock during debug is normally possible if the CPU clock is periodically (typically using a regular timer interrupt) switched on every In that case, a flashloader is required. when a breakpoint is hit) backwards as far as Pin 5 = J-Link-Tx (out), Pin 17 = J-Link-Rx (in). From there on, only the selected device is responsive and can be debugged. 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. This causes the data edges to be recognized by J-Trace delayed, virtually creating a setup time for the trace data. Minhang District, Shanghai 201199,
[email protected] A built-in instruction set simulator further reduces the number of required flash operations. SEGGER Homepge. Figure 1. What is special about software breakpoints in flash? Make sure that the IDE does not perform periodic accesses to memory while the target is in a low power mode. The supplied abort handler should be installed (optional). Whether flash breakpoints are available can be verified using the J-Link control panel: Flash breakpoints can be used in all debuggers which use the proper J-Link API to set breakpoints. The commercial, widely used debug probes from Segger include the J-Link (shown in Figure 3) and the J-Trace, a considerably more advanced and capable debug probe suitable for industrial applications. In command line based applications, like J-Link Commander, specific commands might be available for that purpose. Pin 3 (TRST) should be connected to target CPUs TRST pin (sometimes called NTRST). If the pull-up/pull-down combination is used, their resistance values must be selected so that their parallel combination equals the PCB track impedance. Stand-alone (Q)SPI flash programming application. Termination is almost certainly necessary, but there are some circumstances where it is not required. executes a handler also allows it to perform some specific operations on debug entry / exit or even periodically during debug mode with almost no delay. Most ARM9 systems with external memory come with separate caches for the instruction bus (I-Cache) and data bus (D-Cache) due to the hardware architecture. speed which both, target and J-Link can handle. Debug output connector. This is a standard procedure that most debuggers are capable of, however, this usually requires the program to be located in RAM. Gardner, MA 01440,
[email protected] To set the board up with J-Link, the following steps are required: Solder a 3-pin pin strip to the debug connector pads. GUI-based configuration tool for J-Link. It is used to provide information to the J-Link web control panel. If the processor enters debug state with caches enabled, J-Link / J-Trace does the following: In general, the VCOM feature can be disabled and enabled for debug probes which comes with support for it via J-Link Commander and J-Link Configurator. The following table is valid for J-Trace Pro V2 and later. The figure on the right shows a host, debugging two CPU cores with two instances of the same debugger, via one J-Link/J-Trace. In general, the unlimited flash breakpoints feature of the J-Link DLL can be used free of charge for evaluation and non-commercial use. The setup for the debugger is the same as for downloading into QSPI flash. double click the GDB SEGGER J-Link Debugging group, or select it and click the top leftmost New button. A code coverage analyzer measures the execution of code and shows how much of a source line, block, function or file has been executed. This section describes functionality and how to use J-Link and J-Trace. it is assumed that this application does not change during the debug session. The DCC abort handler assembly file has to be added to the application. The CPU is started and stopped only once. J-Link supports flash breakpoints for a large number of microcontroller devices. Below, a small description of how to use use them to configure the feature is given. To rule out setup related issues, please refer to the following articles: The J-Link DLL / J-Flash checks the write protection on connect (e.g. The J-Link DLL comes with a lot of flash loaders that allow direct programming of internal flash memory for popular microcontrollers. It can be used as a metric for the complexity of a system and can highlight where computing time is spent. 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. and so allow to address many devices on the same PCB with just one debug connector. The setup and behavior is the same as if download into internal flash. on microcontrollers with fast flash the difference between software breakpoints in RAM and flash is hardly noticeable. This ensures there are no synchronization problems over the JTAG interface. Target power supply via Pin 19 is not active. This connector type is very robust (e.g. Order Nr: KIT_XMC_LINK_SEGGER_V1 (this may change in future versions). A sample for such a HardFault handler can be downloaded from the SEGGER website, file: "Generic SEGGER HardFault handler". If this happens, instead of entering debug mode, a HardFault is triggered. J-Link expects UART encoding. Command line tool for handling specific STM32 processors. Can be set to 0-3, 0xFF is default which means USB-Address 0. any other application using J-Link / J-Trace. Selects the maximum JTAG speed handled by the TAP controller. Instruction trace allows reproducing what instructions have been executed by the CPU in which order, which conditional instructions have been I am having trouble uploading and debugging using platformio in VSCode. In order to communicate with a SWD device, J-Link sends out data on SWDIO, synchronous to the SWCLK. J-Link uses indicators (LEDs) to give the user some information about the current status of the connected J-Link. In general, J-Link can be used with any cores listed, even if it does not provide internal flash. There is nothing special to be done by the user to also enable download into a QSPI flash connected to a specific device. It programs the data into flash and waits for new data from the host. J-Link / J-Trace handles cache cleaning directly through JTAG commands. Box Contents. Software overview Tag-Connect replacement debug/programming cables save cost and space on every board! On debug session start, J-Link will send a special sequence that contains the
and which makes sure Known compatible debuggers / debug interfaces are: Known incompatible debuggers / debug interfaces: Many modern CPUs allow direct execution from QSPI flash in a so-called "QSPI area" in their memory-map. is user's responsibility and is expected by the J-Link software to be done prior to performing accesses to the specified CFI area. Raspberry debug interface connection. Target power supply via Pin 19 is active. Monitor codes for different cores are available from SEGGER upon request via the Support ticket system.