Ttelmah
Joined: 11 Mar 2010 Posts: 19360
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Posted: Wed Mar 21, 2012 4:25 am |
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452, does not have internal oscillator. This is why it is not in the data sheet....
If you look at a chip that does (for instance the 4520, which is a latter equivalent chip), and look at the 'oscillator types' section in the data sheet, you see:
"PIC18F2420/2520/4420/4520 devices can be operated
in ten different oscillator modes. The user can program
the configuration bits, FOSC3:FOSC0, in Configuration
Register 1H to select one of these ten modes:
1. LP Low-Power Crystal
2. XT Crystal/Resonator
3. HS High-Speed Crystal/Resonator
4. HSPLL High-Speed Crystal/Resonator
with PLL enabled
5. RC External Resistor/Capacitor with
FOSC/4 output on RA6
6. RCIO External Resistor/Capacitor with I/O
on RA6
7. INTIO1 Internal Oscillator with FOSC/4 output
on RA6 and I/O on RA7
8. INTIO2 Internal Oscillator with I/O on RA6
and RA7
9. EC External Clock with FOSC/4 output
10. ECIO External Clock with I/O on RA6"
Entries 7, and 8.
Best Wishes |
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