Software turns device into high-speed CMSIS-DAP debug probe

Update: April 21, 2021

SEGGER’s latest J-Link software makes it attainable to turn J-Link into a high-speed CMSIS-DAP debug probe. In this mode, it can be employed with any toolchain or application that is compatible with this standard, including pyOCD, KEIL MDK and Arm Development Studio.

This mode is offered for J-Link BASE, J-Link PLUS, J-Link EDU, J-Link ULTRA+ and J-Link PRO. These intelligent debug probes use a 480 Mbps high-speed USB connection to remove idle periods and drive the target interface at its full speed, up to 50 MHz on J-Link ULTRA+ and PRO.

“In addition to its own API and the standard GDB protocol, J-Link now supports CMSIS-DAP operation, a simple, low-level USB protocol for debug probes,” says Rolf Segger, founder of SEGGER. “While CMSIS-DAP doesn’t deliver the same performance as the J-Link protocol, it is widely supported. We decided to add support for it to make J-Link even more universal. J-Link is now the fastest CMSIS-DAP debug probe that we are aware of. One probe fits all.”

“All SEGGER products flow from the same philosophy of high-quality, reliability, speed, ease-of-use and universality,” says Ivo Geilenbrügge, managing director at SEGGER. “Combining J-Link with a 3rd-party or open-source program that uses CMSIS-DAP is now as simple as plug-and-play.”