CONFIG1H.FOSC<3:0> #fuses not working

UpInSmoke01 · Joined: 16 Sep 2013 Posts: 5

Setup:
* I am using: PIC18LF46K22.
* I am using compiler version 4.128
* I build from in MPLab 8.84

Problem:
I am trying to set the:
CONFIG1H.FOSC<3:0>: Oscillator Selection bits
... but can't get it to work

I tried doing this two ways:
1) Through code - I check the "Configuration bits set in code" in MPLAB and then recompile with different #fuses (INTRC_IO, INTRC, LP, ...).
2) Through MPLAB - Configure->Configuration Bits dialog.

...then I check the hex file produced by the build, but it always has the same CRC.

I see from this post:
http://www.ccsinfo.com/forum/posting.php?mode=newtopic&f=1

“Don't compile with the "Build Configuration" in MPLAB set to "DEBUG".
The PROTECT, WDT, BROWNOUT, and maybe some other fuses are
automatically disabled for Debug mode.”

However, my ‘Build Configuration’ is set to ‘RELEASE’.

I also did some tests where I look at the .hex file after compiling with other #fuses changed. These do indeed change the build output.

Build1
//CONFIG1H.PLLCFG:
#fuses PLLEN
//#fuses NOPLLEN
:0E0000000018173800A081000FC00FE00F405D
:00000001FF
;PIC18LF46K22
;CRC=27E3 CREATED="20-Nov-13 18:16"

Build2
//CONFIG1H.PLLCFG:
//#fuses PLLEN
#fuses NOPLLEN
:0E0000000008173800A081000FC00FE00F406D
:00000001FF
;PIC18LF46K22
;CRC=B821 CREATED="21-Nov-13 10:46"

Build3
//CONFIG3H.CCP2MX
//#fuses CCP2B3
#fuses CCP2C1
:0E0000000018173800A181000FC00FE00F405C
:00000001FF
;PIC18LF46K22
;CRC=8544 CREATED="21-Nov-13 10:50"

Can someone tell me why CONFIG1H.FOSC<3:0> #fuses settings have no effect?

temtronic · Posted: Thu Nov 21, 2013 2:56 pm

any chance you've got ICD set to true or yes ?

I like the 46k22, always set fuses within the program not by MPLAB and have never had any problems....

hth
jay

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Until you post a test program, nothing much can happen, because we don't
know what you're doing. If you don't post one, then we have write one
and it won't match your problem.

For example, I install vs. 4.128 and compile this program:

Ttelmah · Joined: 11 Mar 2010 Posts: 19366

It's worth saying that there are _three_ things that set you to 'DEBUG'.

1) MPLAB. Default build configuration in DEBUG, and this overrides CCS settings.
2) DEBUG fuse.
3) ICD=TRUE. Automatically sets the debug fuse.

Any of these force the debug mode to be selected. _All_ need to be turned off.

Best Wishes

temtronic · Posted: Fri Nov 22, 2013 6:37 am

re :
1) MPLAB. Default build configuration in DEBUG, and this overrides CCS settings.

...

you can select 'RELEASE' to be the default build configuration !

If you build in 'DEBUG' mode,burn the PIC, try to run in the real world, it won't work as expected....

hth
jay