Oscillator cannot be configured with INTRC_OSC_CLKOUT for the PIC12F683

[Dave Schindel]

I was using Great Cow Graphical Basic to make a simple timer program for a project. Everything was going well and the complied code worked.

I then I wanted to change the clock speed from 4 MHz to 125KHz to reduce power so I made the configuration setting change in the PROGRAM>HARDWARE SETTINGS menu of great cow graphical basic.

I then decided it would be nice to make sure the oscillator was really running at 125KHz so I also changed from INTRC_OSC_NOCLKOUT to INTRC_OSC_CLKOUT. After compiling and burning the hex into the 12F683, I then checked the frequency output on the CLK OUT pin of the 12F683 and found it was around 1 MHz. This should be 125KHz/4 or 31.25Khz so I looked at the assembly file generated by great cow and noticed that it did not generate the oscillator configuration part of the code that it did when I selected INTRC_OSC_NOCLKOUT.

The assembly code for the OSCCON register was completely missing. I was able to get things working by adding the OSCCON code in and using MPLAB to create the working HEX file but that is extra work that is a hassle to do so wanted to point out this bug. Attached are some screen shots to help clarify my settings. I highlighted the code that is missing when I tried to configure the clock as INTRC_OSC_CLKOUT.

[Anobium]

Opps. Can you post the errant program?. So, we can reproduce and fix.

Post the GCB and the ASM GCGB created to the post, as attachments.

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However, I have resolved in build 1120

As a user of GCGB I have no idea how you installed but you need to update to the latest build regardless to get build 1120.

[Dave Schindel]

How can I check which build I have?
The Great Cow Basic code I used was very short just to test this. It is:

;Chip Settings
#chip 12F683,0.125
#config OSC=INTRC_OSC_CLKOUT

The assembly generated by Great Cow Basic was:

;Program compiled by Great Cow BASIC (0.99.01 2022-01-27 (Windows 64 bit) : Build 1073) for Microchip MPASM
;Need help? See the GCBASIC forums at http://sourceforge.net/projects/gcbasic/forums,
;check the documentation or email w_cholmondeley at users dot sourceforge dot net.

;********************************************************************************

;Set up the assembler options (Chip type, clock source, other bits and pieces)
 LIST p=12F683, r=DEC
#include <P12F683.inc>
 __CONFIG _FCMEN_ON & _CPD_OFF & _CP_OFF & _MCLRE_OFF & _WDTE_OFF & _INTRC_OSC_CLKOUT

;********************************************************************************

;Vectors
    ORG 0
    pagesel BASPROGRAMSTART
    goto    BASPROGRAMSTART
    ORG 4
    retfie

;********************************************************************************

;Start of program memory page 0
    ORG 5
BASPROGRAMSTART
;Call initialisation routines
    call    INITSYS

;Start of the main program
;Chip Settings
BASPROGRAMEND
    sleep
    goto    BASPROGRAMEND

;********************************************************************************

;Source: system.h (156)
INITSYS
;asm showdebug _For_selected_frequency_-_the_external_oscillator_has_been_selected_by_compiler ChipMHz
;asm showdebug _Complete_the_chip_setup_of_BSR,ADCs,ANSEL_and_other_key_setup_registers_or_register_bits
;Ensure all ports are set for digital I/O and, turn off A/D
;SET ADFM OFF
    bcf ADCON0,ADFM
;Switch off A/D Var(ADCON0)
;SET ADCON0.ADON OFF
    bcf ADCON0,ADON
;ANSEL = 0
    banksel ANSEL
    clrf    ANSEL
;CMCON0 = 7
    movlw   7
    banksel CMCON0
    movwf   CMCON0
;
;'Turn off all ports
;GPIO = 0
    clrf    GPIO
    return

;********************************************************************************


 END

[Anobium]

Thank you. You have (0.99.01 2022-01-27 (Windows 64 bit) : Build 1073) build 1073.

You need build 1121.

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Goto https://sourceforge.net/projects/gcbasic/files/Release%20Candidates/Patches/

• Download the zip
• unzip all files to a temp folder
• apply all files to your installation replacing all the existing files
• then, rename the compiler EXE for your operating system - you need to ensure either GCBASIC64.exe or GCBASIC32.exe is renamed as GCBASIC.exe for your operating system
• Enjoy

Using single files may make your installation unstable. Use all the patch files.

See https://1drv.ms/x/s!Ase-PX_n_4cvhJAysbPF3VJAnYaj3A for changelog.

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There was an issue in build 1120... it always set the CLOCKOUT.. you need 1121. I will post when I have uploaded.

[Anobium]

Uploaded build 1121

Goto https://sourceforge.net/projects/gcbasic/files/Release%20Candidates/Patches/

1. Download the zip
2. unzip all files to a temp folder
3. apply all files to your installation replacing all the existing files
4. then, rename the compiler EXE for your operating system - you need to ensure either GCBASIC64.exe or GCBASIC32.exe is renamed as GCBASIC.exe for your operating system
5. Enjoy

Do not use single files from the zip - this may make your installation unstable. Use all the patch files.

See https://1drv.ms/x/s!Ase-PX_n_4cvhJAysbPF3VJAnYaj3A for changelog.

[Dave Schindel]

Everything worked smoothly with the new 1121 build. Thanks for the fast update!

[Anobium]

Pleasure, a worthwhile change. I will expand this change over the next few weeks.