Segger J-Link - Silicon Labs

J-Link / J-Trace (UM08001) © 2004-2017 SEGGER Microcontroller GmbH & Co. KG
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15.15 Silicon Labs
J-Link has been tested with the following Silicon Labs devices:
• EFM32G200F16
• EFM32G200F32
• EFM32G200F64
• EFM32G210F128
• EFM32G230F32
• EFM32G230F64
• EFM32G230F128
• EFM32G280F32
• EFM32G280F64
• EFM32G280F128
• EFM32G290F32
• EFM32G290F64
• EFM32G290F128
• EFM32G840F32
• EFM32G840F64
• EFM32G840F128
• EFM32G880F32
• EFM32G880F64
• EFM32G880F128
• EFM32G890F32
• EFM32G890F64
• EFM32G890F128
• EFM32TG108F4
• EFM32TG108F8
• EFM32TG108F16
• EFM32TG108F32
• EFM32TG110F4
• EFM32TG110F8
• EFM32TG110F16
• EFM32TG110F32
• EFM32TG210F8
• EFM32TG210F16
• EFM32TG210F32
• EFM32TG230F8
• EFM32TG230F16
• EFM32TG230F32
• EFM32TG840F8
• EFM32TG840F16
• EFM32TG840F32
• EM351
• EM357
15.15.1 EFM32 series devices
15.15.1.1SWO
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).
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 run-
ning at 14 MHz, to make SWO speed auto-detection work, no matter what speed the
CPU is really running at.