What's Happening at SEGGER?

2012 |
Dec. 21
J-Link, Press Releases 2012
J-Link Control Panel Flash Download

J-Link is Fastest in Flash Programming

After a recent upgrade to the J-Link hardware and further improvements to the software, the industry leading J-Link has been subjected to a flash programming speed comparison against various debug probes. The results show, that even the base model of the J-Link outperforms the competition. All tests have been performed on the same target chip, STM32 with blank flash memory.

Test Scenario

The speed tests have been made with different debug probes and software under the same test conditions. The I-jet and ST-Link V2 were tested with IAR Embedded Workbench for ARM. The ULINKpro was tested with KEIL uVision. The J-Link base model of the 2013 hardware (v9) was tested with the IAR Embedded Workbench for ARM, KEIL uVision, and the J-Link Commander version 4.59a (test utility included freely with the J-Link related software package). All tests have been performed by placing a 512 KB program into the flash memory of a blank STM32F417IG microcontroller connected via SWD interface. Tests via JTAG interface gave similar results.

Test Results

 ProbeConfigurationTime [s]Speed [KB/s]
1J-LinkJ-Link Commander (v4.59a)2.1244
2J-LinkIAR EWARM (v6.40.2)3.1165
3J-LinkKEIL uVision (v4.60)3.1165
4J-LinkemIDE (v120814)3.2160
5ULINKproKEIL uVision (v4.60)8.660
6I-jetIAR EWARM (v6.40.2)18.827
7ST-LINKIAR EWARM (v6.40.2)35.115


J-Link Speedtest

“Flash Download performance has a significant impact on debug turn around times. This Flash-Download performance comparison shows once again that J-Link plays in a league of its own, as even our base model clearly outperforms every other emulator we have tested with”, says Rolf Segger, Founder, and CTO of SEGGER.

More details on the performance comparison can be found at the address:



About J-Link

The SEGGER J-Link is the most popular debug probe on the market. It is tool chain independent and works with free GDB-based tool chains such as emIDE and Eclipse, as well as commercial IDEs from: Microchip (MPLAB® X), Atmel, Atollic, Coocox, Cosmic, Freescale, IAR, KEIL, Mentor Graphics, Python, Rowley, Renesas, Tasking and others. With the J-Link family, investments in the debug probe are preserved when changing compiler or even CPU architecture.

J-Link supports multiple CPU families, such as ARM 7, 9, 11, Cortex-M0, M0+, M1, M3, M4, R4, A5, A8, A9 as well as Renesas RX100, RX200, RX610, 620, 62N, 62T, 630, 631, 63N and Microchip PIC32; there is no need to buy a new J-Link or new license when switching to a different yet supported CPU family or tool-chain. SEGGER is also continuously adding support for additional cores, which in most cases, only requires a software/firmware update. Unlimited free updates are included with even the baseline model of the J-Link family. SEGGER is excited to continue advanced development of its cutting edge embedded tool solutions to be utilized with pretty much any development environment you choose. All J-Links are fully compatible to each other, so an upgrade from a lower-end model to a higher-end model is a matter of a simple plug-and-play.

Full product specifications are available at:
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