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CALIBRATING THE RC OSCILLATOR OF THE ST7FLITE0 MCU USING THE MAINS

4.1.5 Detailed basic version software flowchart

CLEAR RAM BYTES

ENABLE INPUT CAPTURE INTERRUPT

(NBOVER, CR)

STORE STARTING VALUE

80H --> VALUE

80H --> RCCR

EDGE

ON LTIC

INPUT

STORE CAPTURED VALUE IN CAPTURE 1

ENABLE TIMEBASE INTERRUPT TO

STORE CAPTURED VALUE IN CAPTURE 2

DISABLE TIMEBASE AND INPUT CAPTURE

INTERRUPTS

START TO COUNT TIMER OVERFLOWS

DIVIDE VALUE BY 2

CALCULATION OF:

NBOVER X F9 + CAPTURE 2 - CAPTURE 1

EDGE

ON LTIC

INPUT

SUBTRACT VALUE TO RCCR

ADD VALUE TO RCCR

RC OSCILLATOR IS TRIMMED TO 1 MHZ

COMPARE

RESULT WITH

138H

IS THE

DICHOTOMY

FINISHED?

NO

NO

NO

YES

YES

YES

SMALLER

GREATER