Keil Logo

ULINK: SWD Communication Failure Using EFM32 Development Boards


Information in this knowledgebase article applies to:

  • ULINKPro
  • ULINK2
  • J-Link PLUS
  • EFM32 Development Boards

SYMPTOM

The error SWD Communication Failure can occur when attempting to debug any EFM32 devices.

RESOLUTION

One attempt to work around this issue is to adjust the Max Clock option. The following settings demonstrate how to adjust Max Clock appropriately for the EFM32LG-DK3650 development board. Note that these settings may vary for other development boards and debuggers.

  • ULINKpro: Using the 0.05" 20-pin Cortex-M Debug+ETM connector, it is possible to connect with frequencies from 5kHz to 20 MHz.
  • ULINK2:
    • Using the 0.10" 20-pin ARM JTAG connector it is possible to connect with frequencies up to 10Mhz
    • Using the 0.05" 20-pin Cortex-M Debug+ETM connector with the 10-pin to 20-pin adapter cable, connections remain working with all frequencies except from 10 MHz
  • J-Link Plus:
    • Connection to 0.10" 20-pin ARM JTAG connector works up to
    • Connection to 0.05" 20-pin Cortex-M Debug+ETM connector using the 10-pin to 20-pin adapter cable works does not work for 5MHz and 10 MHz.

Note

  • EFM32 boards must be configured to the proper Debug Mode before it will enable the external Debug or Trace connectors. The EnergyAware Commander tool in Silabs Simplicity Studio allows you to change the Debug Mode via the on-board J-Link (Mini-USB connector). By default the Debug Mode is set to MCU. To use an external debug adapter such as ULINKpro, the Debug Mode should be set to In or Off. To do this, with the EnergyAware Commander tool, click the Connect button, then change the Debug Mode setting to In or Off, then click the Disconnect button.

SEE ALSO

Last Reviewed: Friday, December 18, 2015


Did this article provide the answer you needed?
 
Yes
No
Not Sure
 
  Arm logo
Important information

This site uses cookies to store information on your computer. By continuing to use our site, you consent to our cookies.

Change Settings

Privacy Policy Update

Arm’s Privacy Policy has been updated. By continuing to use our site, you consent to Arm’s Privacy Policy. Please review our Privacy Policy to learn more about our collection, use and transfers
of your data.