INTOSC madness

• INTOSC madness
  Posted by PerranOak on 11 Mar, 2021 19:10
• I'm using a 12F683 and have been setting FOSC = INTOSCIO and everything is fine.
  
  Then I changed things (extra info included, the only other thing I changed was the freq from 4MHz to 1MHz):
  

  Code: [Select]

  #include <xc.h>
#include <stdio.h>
#include <stdlib.h>
#define _XTAL_FREQ 1000000

#pragma config FOSC = INTOSC
  This is so I can output the clock.
  
  Now I get this error:
  683_Shift_Reg.c:14:: error: (1363) unknown configuration setting/register (FOSC = INTOSC) used
  
  Could I please have a clue as to where to look for the right command, cheers.
• #1 Reply
  Posted by Doctorandus_P on 11 Mar, 2021 19:57
• Set _XTAL_FREQ back to 4MHz?
  
  
  Or:
  Use your IDE to seach through the "library" code & header files for "_XTAL_FREQ" and how it is used.
  It's likely that dependent on different ranges of values different settings are chosen, and the settings for 1MHz apparently do not agree with FOSC = INTOSC.
  
  You can of course also search for those macro names.
• #2 Reply
  Posted by cv007 on 11 Mar, 2021 20:28
• Look in pic/dat/cfgdata/12f683.cfgdata-
  
  INTOSCCLK is probably what you are looking for (or a couple other name variations).
  
• #3 Reply
  Posted by hexreader on 11 Mar, 2021 21:00
• cv007 is of course correct with INTOSCCLK
  
  The way I would have found this is:
  
  From the MPLABX IDE Select:
  
   - Production
   -       Set Configuration Bits
   -            to the right of field FOSC select the down arrow
   -                choose from the drop-down list
  
  Either "Generate Source Code To Output" and copy/paste the resulting output to your code window, or manually edit as you prefer
• #4 Reply
  Posted by jpanhalt on 11 Mar, 2021 21:54
• Probably I misunderstand.  Do you want intosc out using the internal oscillator or a crystal?
  
  The setting for 1MHz is b'0100xxxx' in the OSCCON register if using the internal oscillator.  If using a crystal, it doesn't matter.  Then in configuration, you need to define INTOSCIO or INTOSC and so forth.
• #5 Reply
  Posted by PerranOak on 13 Mar, 2021 18:20
• Thank you all very much.
  
  I wanted to output the internal oscillator. It wasn't the freq that was the problem, thanks, see below.
  
  Thank you, the command: INTOSCCLK worked perfectly.
  
  I had completely forgotten about the "Set Config Bits" pull-downs. I generally copy all that stuff from previous projects and alter the things I need to, hence my INTOSC error. I will  use that in future, thank you.
  
  Interestingly, I looked in the file, 12f683.cfgdata and found:
  CVALUE:5:INTOSCCLK,_INTOSC,_INTRC_OSC_CLKOUT:INTOSC oscillator: CLKOUT function on RA4/OSC2/CLKOUT pin, I/O function on RA5/OSC1/CLKIN
  
  Of course, INTOSCCLK worked but, for fun, I tried: _INTOSC.
  This output the clock at the expected freq but instead of being a nice, sharp square wave, it's edges were curved like you get when there is lots of capacitance around.
  When I went back to INTOSCCLK it was the nice, sharp wave again.
  
  Not a problem, just interesting.