Firmware update of the bootloader using Segger J-Link and SWD interface

SWD J-LINK Bootloader update 

Serial Wire Debug (SWD) is a 2-pin (SWDIO/SWCLK) electrical alternative JTAG interface that has the same JTAG protocol on top. SWD uses an ARM CPU standard bi-directional wire protocol, defined in the ARM Debug Interface documentation. It can be used to access SoC/module internal resources and perform basic erase/ read/ write operations on embedded flash. The steps below describe the update of the internal flash with the new bootloader image using SWD inetrface.


  • Open J-link utility (e.g.: windows location: C:\Program Files (x86)\SEGGER\JLink)

  • Connect to the target: connect

  • Select device: EFR32MG22CXXXF512

  • Specify target interface: SWD

  • Specify target interface speed: 1000kHz

  • Perform target reset: r

  • Erase bootloader sectors: erase 0x0 0x6000

  • Program the bootloader image: loadfile c:\prj\bootloader.bin 0x0

  • Restart the module using the “Reset” button on the Lyra board
  • Please note, the LED on the board can be used to indicate that status of the update