David Boyd

Activating The External Oscillator on QG8

Discussion created by David Boyd on Apr 29, 2007
Latest reply on Apr 30, 2007 by Alban Rampon
I am trying to get a 32.768kHz watch crystal to oscillate on a QG8. However despite trying various ICS register options I have had no luck - the chip continues to run on the internal oscillator.  I know this as I can trim the oscillator and see a frequency change on a port I am using as a freq-out pin.
 
Here is the code I am using.  I have tried toggling HGO on and off as well. I am using FFL Engaged External (FEE) mode.

 lda    #%00000110     ;Set EREFS and ERCLKEN
  sta   rICSC2
  lda   #%00000000
  sta   rICSC1
With a 32,768Hz crystal this equals a bus clock of 8,388,608 Hz.
Advice appreciated.
 
Davo

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