Difference between revisions of "EFM32"

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(Created page with "__TOC__ This article describes device specifics of the Silicon Labs EFM32 series devices == SWO == Usually, the SWO output frequency of a device is directly depende...")
 
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This article describes device specifics of the Silicon Labs EFM32 series devices
 
This article describes device specifics of the Silicon Labs EFM32 series devices
 
== SWO ==
 
== SWO ==
  +
Auto SWO speed calculation of J-Link does not work for the Silicon Labs EFM32 series devices.
Usually, the SWO output frequency of a device is directly dependent on the CPU speed. The SWO speed is calculated as: <CPUFreq> / n. On the EFM32 series this is not the case:
 
The SWO related units (ITM, TPIU, ...) are chip-internally wired to a fixed 14 MHz
 
clock (AUXHFRCO).
 
   
  +
Normal SWO Speed calculation: <CPUFreq> / n
This will cause the auto-detection of J-Link to not work by default for these devices, if the CPU is running at a different speed than AUXHFRCO. All utilities that use SWO speed auto-detection, like the J-Link SWOViewer, need to be told that the CPU is running at 14 MHz, to make SWO speed auto-detection work, no matter what speed the CPU is really running at.
 
  +
  +
EFM32 specific:Chip-internally wired to a fixed 14 MHz clock (AUXHFRCO)
  +
  +
For utilities like J-Link SWOViewer or similar:
  +
Select 14 MHz as CPU speed (no matter what the CPU is really running at) to make the normal calculation working

Revision as of 17:00, 21 July 2017

Contents

This article describes device specifics of the Silicon Labs EFM32 series devices

SWO

Auto SWO speed calculation of J-Link does not work for the Silicon Labs EFM32 series devices.

Normal SWO Speed calculation: <CPUFreq> / n

EFM32 specific:Chip-internally wired to a fixed 14 MHz clock (AUXHFRCO)

For utilities like J-Link SWOViewer or similar: Select 14 MHz as CPU speed (no matter what the CPU is really running at) to make the normal calculation working