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stoyanoff
Joined: 20 Jul 2011
Posts: 375
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| PIC18F67K22 oscillator problem |
 Posted: Sun Jun 22, 2014 12:48 am |
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Greetings! I`m not very familiar with this controller. I connected a 10M quartz with 15pF caps as an oscillator.
Here are my fuse settings:
| Code: |
#include <18F67K22.h>
#FUSES HSH,NOWDT
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The problem is with the delay function. I have to set clock=40M to have a correct delay time. Am I using some kind of PLL?!
Thanks! |
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temtronic
Joined: 01 Jul 2010
Posts: 9202
Location: Greensville,Ontario
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| Posted: Sun Jun 22, 2014 5:54 am |
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yes....please look at figure 3-1 of the datasheet to see the 'flow' or signal path for using your 10MHz xtal/caps to get 40MHz. It'll have to go through the 4xPLL to get 'up to speed'.
Nice chip as you can use the internals (4,8,16MHz)to input to the 4xPLL !!
too many PICs...never enough time to play with them !
cheers
Jay |
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dyeatman
Joined: 06 Sep 2003
Posts: 1931
Location: Norman, OK
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| Posted: Sun Jun 22, 2014 7:28 am |
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In the datasheet, HSH is High Power mode where the chip has to run in the
range of 16-25Mhz (Table 3-1). Therefore, with a 10Mhz oscillator the PLL
is automatically set to on. However, the inputs are not biased
properly for 10Mhz. If you use HSM it should run at 10Mhz and it will be
biased properly.. You can then use the PLLEN fuse if needed.
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