lerameur
- 28th February 2011, 01:19
HI,
I am trying to use external oscillation on a P18F4550. The spec sheet says to use 15pF caps. But it is not operating at 20Mhz. With the code I used below. the only config thats works and I can confirm on the oscilloscope is using a 10Mhz crystal with 20pF caps. ( but config at OSC 20)
Tried multitude of capacitors values with the 20Mhz crystals. Any ideas ?
OSCCON = %01111100
DEFINE OSC 20
K
I am trying to use external oscillation on a P18F4550. The spec sheet says to use 15pF caps. But it is not operating at 20Mhz. With the code I used below. the only config thats works and I can confirm on the oscilloscope is using a 10Mhz crystal with 20pF caps. ( but config at OSC 20)
Tried multitude of capacitors values with the 20Mhz crystals. Any ideas ?
OSCCON = %01111100
DEFINE OSC 20
K