What does oscillator tuning do in PIC18F?

[matrixofdynamism]

The page 28 in https://ww1.microchip.com/downloads/en/devicedoc/39632c.pdf describes the OSCTUNE register. What do the Frequency tuning bits do? When it says maximum and minimum frequency, how does one know what these maximum and minimum frequency values are?

 

[FvM]

See this Microchip application note https://ww1.microchip.com/downloads/en/AppNotes/00244a.pdf

It says that the tuning range is +/- 12%, I never checked it.

 

[paulfjujo]

hello,


i wrote a program to test OSCTUNE...
FOSC output on PIN MCU -> Frequencemeter

/ 16-12-2014
// voir forum Futurascience
// https://forums.futura-sciences.com/electronique/672061-interruptions-uart-pic18-craque.html
/*
FOSC interne 16MHz sortie Fosc/4 sur RA6
Tamb=18,1°C
action sur OSCTUNE.TUN
31 => 4.145 Mhz
0 => 4.006 MHz
32 => 3.873 Mhz

so delta can be around +3% or - 3% on FOSC/4

if interested ,i can post the program test,written for a 18F46K22