PIC18F452 and trouble with clk generation.

[aniketrane]

Sorry to interrupt, but I am also working with PIC18F452 and I am also facing problems with my oscillator. I am using 20 MHz crystal with pair of 33 pF capacitors. I am using PICSTART PLUS programmer by microchip (Firmware updated to V 3.11) and MPLAB IDE 6.3. I have configured my PIC as following:
>Oscillator configuration: EC with osc2 pin as output.
>Watchdog Timer: disabled
>Power up timer: disabled
>brown out detect: disabled
>low voltage programming: enabled
>code protect: disabled
>table read / write protect: disabled

The circuit i am using to generate clock is shown in the diagram

So as a result I should get clk-out on pin 14 (osc2 pin). But I am not getting it. Also I am setting the pins of port B alternately high and low to drive some LEDS, but I am getting no output on the pins (0 – 0.5 V).
The code that I am trying to execute is:

LIST P=PIC18F452
include "P18F452.INC"

org 0000
goto start

start:
CLRF STATUS
CLRF PORTB
CLRF LATB
MOVLW 0x00
MOVWF TRISB
MOVLW 0xAA
MOVWF PORTB
END


I would like to know where I am going wrong.
**broken link removed**

 

[auburnate]

Clock Generation

When I got the 18f452 to work in my embedded project, I did not use any of the external circuitry you have shown. Across the OSC1/OSC2 pins I placed my 20 mhz crystal. Then I ran 22 pf caps to ground on each of those legs. Configure the PIC for HS ( high speed external crystal) and your code might work. Good luck.

Nate

 

[StupidDum]

I usually disable the low voltage programming