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CALIBRATING THE RC OSCILLATOR OF THE ST7FLITE0 MCU USING THE MAINS

1.2 BASIC VERSION

In this version the measurement is done only once for each dichotomization step. This allows

the calibration software to be light and fast. It requires only 90 bytes of program memory and

5 bytes of RAM during calibration. The calibration takes less than 160 ms to be completed

The software works as shown in the following flowchart. The assembly code and a more de-

tailed flowchart can be found in Section 4.

Figure 3. Basic software flowchart

Dichotomization

finished?

Initialization of Lite Timer

Measurement and

Increase RCCR

Decrease RCCR

Clock is set to 1 MHz

smaller

greater or equal

Compare

result with

reference

no

yes

calculation