AN4631 datasheet(23/30 Pages) STMICROELECTRONICS

Numer części	AN4631

Szczegółowy opis	How to calibrate an STM32L0xx internal RC oscillator

PDF	30 Pages

Scroll/Zoom	100%

Producent	STMICROELECTRONICS [STMicroelectronics]

Strona internetowa	http://www.st.com

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Internal RC oscillator calibration

When running the calibration process for the MSI oscillator, the number of steps is equal to

256. If the LSE oscillator is used as the reference frequency (REFERENCE_FREQUENCY =

LSE value / Input capture prescaler = 32768/8 = 4096 Hz) and the selected number of

measured periods is 10, the calibration consumes approximately:

duration = (2 x 11 x 256) / 4096 = 1.4 s

The duration of the calibration process with a maximum allowed error is lower than or equal

to the duration of calibration when using the minimum frequency error process.

Note:

Multiplying by 2 in the duration formula above is due to the fact that there is no

synchronization between the reference signal and the start of counting by the timer.

AN4631 Arkusz danych(PDF) 23 Page - STMicroelectronics