PIC18F4520 Internal Oscillator

[switchblademaster]

Good Day,
I am trying to use the internal oscillator of the PIC18F4520 at 4MHz with PLL on. However I only get it running at 1MHz. Can anyone help me??

[PCM programmer]

When you use the Internal oscillator with the PLL, the only possible
oscillator frequencies are 16 MHz or 32 MHz. There's a schematic
in the 18F4520 data sheet, in the Oscillator section. It shows that
only the 4 MHz and 8 MHz outputs from the internal oscillator can
drive the 4x PLL. So, 4x4 = 16 MHz, and 8x4 = 32 MHz.

If you have a modern version of the compiler, you can set it up
very simply. Just specify internal oscillator in the #fuses and
specify 16 or 32 MHz in the #use delay(). The compiler will set
it up to use the PLL, automatically.