DocID16612 Rev 6

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AN3101

Low speed internal oscillator measurement

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Figure 13. LSI frequency measurement flow

3.3

LSI measurement demo description

The demo provided with this application note shows the importance of measuring the LSI

frequency value before starting to use peripherals clocked by this type of clock. In this

example the independent watchdog (IWDG) is used to generate a reset after 12 ms.

Since the LSI clock is not accurate, the reset will occur slightly after or before the required

time-out. Hence, measuring the LSI frequency enhances the time-out accuracy.