*
0000:  MOVLW  00
0001:  MOVWF  0A
0002:  GOTO   019
0003:  NOP
..................... // Source code file: ENDLESS.C=20
..................... // Program function: Outputs variable count=20
..................... #include <16F877A.h>=20
..................... //////// Standard Header file for the PIC16F877A devic=
e
////////////////=20
..................... #device PIC16F877A=20
..................... #list=20
..................... =20
..................... #use delay(clock=3D4000000)=20
0004:  MOVLW  21
0005:  MOVWF  04
0006:  BCF    03.7
0007:  MOVF   00,W
0008:  BTFSC  03.2
0009:  GOTO   018
000A:  MOVLW  01
000B:  MOVWF  78
000C:  CLRF   77
000D:  DECFSZ 77,F
000E:  GOTO   00D
000F:  DECFSZ 78,F
0010:  GOTO   00C
0011:  MOVLW  4A
0012:  MOVWF  77
0013:  DECFSZ 77,F
0014:  GOTO   013
0015:  GOTO   016
0016:  DECFSZ 00,F
0017:  GOTO   00A
0018:  RETURN
..................... void main()=20
..................... =20
..................... {=20
0019:  CLRF   04
001A:  BCF    03.7
001B:  MOVLW  1F
001C:  ANDWF  03,F
001D:  BSF    03.5
001E:  BSF    1F.0
001F:  BSF    1F.1
0020:  BSF    1F.2
0021:  BCF    1F.3
0022:  MOVLW  07
0023:  MOVWF  1C
..................... while(1)=20
..................... {=20
..................... output_D(255);=20
0024:  CLRF   08
0025:  MOVLW  FF
0026:  BCF    03.5
0027:  MOVWF  08
..................... delay_ms(100);=20
0028:  MOVLW  64
0029:  MOVWF  21
002A:  CALL   004
..................... output_D(0);=20
002B:  BSF    03.5
002C:  CLRF   08
002D:  BCF    03.5
002E:  CLRF   08
..................... delay_ms(100);=20
002F:  MOVLW  64
0030:  MOVWF  21
0031:  CALL   004
..................... }=20
0032:  BSF    03.5
0033:  GOTO   024
..................... }=20
0034:  SLEEP

Configuration Fuses:
   Word  1: 3F73   RC NOWDT PUT BROWNOUT NOLVP NOCPD NOWRT NODEBUG NOPROTEC=
T


this is d .lst file and no isr is here. so what i should do now?
i think there might be a problem in crystal oscillator,so if i use logic
analyzer of pickit 2 to know the frequency then problem will become much
clear.


Joe Wronski wrote:
>=20
>   First, you prove that a prescaler is there (which I doubt).  You can=20
> do that by getting CCS to output a lst file, and you analyze what the=20
> compiler is doing before it gets to main().  You check to see if it is=20
> doing anything with the clock to add a prescaler.  You can also look at=20
> the disassembly to sanity check the values passed to the delay()=20
> function (it's probably a macro).
> My guess is that a floating input pin RBx is causing interrupts and the=20
> isr is using up most of the processors time.  So, you check to see if=20
> the compiler put any isr vectors in there.  And you prevent portb=20
> interrupt on change on floating inputs by enabling portb pullups.
> If you have debugger capabilities, it is easier to do some of these=20
> things by setting breakpoints, examining register contents, and single=20
> stepping.   Inserting dummy code in main() before the loop will let you=20
> set a breakpoint.  The dummy code should do something that doesn't get=20
> optimized out, like "unsigned char n; n =3D PORTB;"
> If it's the watchdog timer, or something else causing a reset, you will=20
> find that if you set a breakpoint before the loop, the breakpoint will=20
> be hit more than once.  You can also set a breakpoint at the isr vector=20
> to see if it is a robue interrupt.
>=20
> Joe W
>=20
>=20
> On 6/18/2011 5:03 AM, geetansh wrote:
>> how can i remove that prescaler then?
>>
>>
>>
>> RussellMc wrote:
>>>> when the delay between on off  was set
>>>> 10ms the leds took 2.3sec
>>> 2300 mS / 10 mS ~~~=3D 256
>>>
>>> Delay MAY be out by a factor of 256, indicating that there is possibly =
a
>>> prescaler in the clock that is not being accounted for.
>>>
>>>
>>>                     Russell
>>> --=20
>>> http://www.piclist.com PIC/SX FAQ&  list archive
>>> View/change your membership options at
>>> http://mailman.mit.edu/mailman/listinfo/piclist
>>>
>>>
>=20
>=20
> --=20
> Joe Wronski
> Stillwater Embedded Engineering
> www.stillwatereng.net
>=20
> --=20
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>=20
>=20

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--=20
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