Difference between revisions of "EFM32"
(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 |
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== SWO == |
== SWO == |
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+ | Auto SWO speed calculation of J-Link does not work for the Silicon Labs EFM32 series devices. |
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− | 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: |
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− | The SWO related units (ITM, TPIU, ...) are chip-internally wired to a fixed 14 MHz |
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− | clock (AUXHFRCO). |
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+ | Normal SWO Speed calculation: <CPUFreq> / n |
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− | 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. |
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+ | EFM32 specific:Chip-internally wired to a fixed 14 MHz clock (AUXHFRCO) |
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+ | For utilities like J-Link SWOViewer or similar: |
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+ | 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