16F631 and crystal problems

I have been having problems with getting a 16F631 to operate correctly. I have tried both an internal and external oscillators. Under both circumstances the code seems to run 2 times faster or more. I have a very basic blinking LED program, 2 seconds on 2 off. I'm using PBP compiler 2.60.

Code:

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@ __config _HS_OSC & _WDT_ON & _MCLRE_OFF & _CP_OFF & _IESO_OFF
'@ __config _INTOSCIO & _WDT_ON & _MCLRE_OFF & _CP_OFF & _IESO_OFF

Clear
define osc 10
'define osc 8

OSCCON = %01101110      'external 10 mhz
'OSCCON = %01111111        'internal 8 mhz

ANSEL = 0              'set port to digital
OPTION_REG.7 = 0        'enable pull ups on A and B

TRISA = %011000        '
TRISB = %11001111      '
TRISC = %11111111      '

PORTA = 0

Pause 500
fake_main:

    PORTA.0 = 0
    pause 2000
    PORTA.0 = 1
    pause 2000
             
goto fake_main

end

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This problem is frustrating me and is probably either very obvious or very difficult.

Thanks for the help

First, it is a good idea to turn off/disable the comparators:
from the data sheet

Quote:

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8.2.1
COMPARATOR ENABLE
Setting the CxON bit of the CMxCON0 register enables
the comparator for operation. Clearing the CxON bit
disables the comparator resulting in minimum current
consumption.

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Then, if you are using a 10MHz external, do not use the OSCCON register.
If using the internal then set OSCCON to 01110000 for 8MHz.

Hello Luckyborg,
The aspstrophe ' symbol works in pbp to assign text as a comment, it supposedly does not work in assembly, and should be replaced with an semicolon ;
'@ __config _INTOSCIO & _WDT_ON & _MCLRE_OFF & _CP_OFF & _IESO_OFF
;@ __config _INTOSCIO & _WDT_ON & _MCLRE_OFF & _CP_OFF & _IESO_OFF
I would think MPASM would choke, who knows.
EDIT: also DEFINES are "supposed" to be in all UPPERCASE LETTERS

Quote:

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The aspstrophe ' symbol works in pbp to assign text as a comment, it supposedly does not work in assembly, and should be replaced with an semicolon ;

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True when it's AFTER the @ symbol or Within and ASM/ENDASM block, it doesn't apply it the current case.

But yes, OSC reswerved word HAVE TO BE IN UPPERCASE

Quote:

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Originally Posted by mister_e

True when it's AFTER the @ symbol or Within and ASM/ENDASM block, it doesn't apply it the current case.

But yes, OSC reswerved word HAVE TO BE IN UPPERCASE

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Hi Steve,
Ok so that's the Magic, before the @ it works, after it doesn't, got it . . . for now :D Getting pretty foggy behind these eyes . . .

Thanks everyone. The problem was osc instead of OSC. The comparators are disabled on this chip by default, at least according to my 2006 preliminary datasheet I have, though I'll download the current version just to make sure nothing has changed. Can someone explain what

Code:

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DEFINE osc 10

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would do, or is it just ignored? I've never intentionally used a DEFINE with anything other than a reserved word. Does it behave similar to

Code:

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osc CON 10

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Thanks again for the help. I'm very glad it was under the something obvious category.

Yup, they are off by default, that is why I said, "a good idea". One line of code to be sure.

DEFINE OSC XX 'Tells PBP the speed the chip is running at so it can calculate timing functions such as PAUSE.