18f26k80 oscillator

paolope · Joined: 29 May 2009 Posts: 7

hello,
whatever I do, the chip runs at about 7.97Mhz (internal RC)

I tried with #use delay (crystal=6.144M)
I tried with #fuses HSM or even HSH.

Any idea?
I feel very stupid and frustrated. In this condition the 4xPLL option is far away.

Paolo

dyeatman · Joined: 06 Sep 2003 Posts: 1934 Location: Norman, OK

It would help to see what you have so far.
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paolope · Joined: 29 May 2009 Posts: 7

Here is adc.h:

Ttelmah · Joined: 11 Mar 2010 Posts: 19510

Where is your crystal connected?. OSC1/2, or SOSCI/O?. You are enabling the secondary oscillator as the clock source. Unless your crystal is on the secondary pins, it won't run, so the system will drop back to the internal oscillator. Given you are talking about wanting to use the PLL (which is only available on the primary oscillator), I'd guess your crystal is on the primary pins.
Remember fuses 'or' together, so the '00' pattern selected by HSM or H to use the primary oscillator, 'ored' with SOSC_DIG, gives the pattern for SOSC_DIG....

HSM, PLLEN, NOFCMEN, NOIESO, PUT
#use delay(crystal=6.144M, clock=24.576M)

Best Wishes

paolope · Joined: 29 May 2009 Posts: 7

Mr Murphy states that 'things left alone go from bad to worse'...
in effect NOIESO crashes the debugger-ICDU64 which is then not able to control the PIC, so nothing new happens