How to set 18F2520 for INT OSC?

[circuitpro]

How in the world do you set a 18F2520 to use it's INTERNAL oscillator @ 8 MHz? I've got
OSCCON set like this

OSCCON = %01110010

but still not running. On the melabs serial programmer, the only INTernal osc settings are INTRC (INTIO1), and INTRC (INTIO2). Are those correct?

Very confused.

[circuitpro]

I guess it is oscillating, but it takes 25 seconds to start! I assume that has to do with the delay timers. :(

[mackrackit]

Give up try to set the fuses with the programmers software and set them in the *.inc file or code space
http://www.picbasic.co.uk/forum/showthread.php?t=543

Then as the above link explains, goto the MPASM Suite directory and look at the P18F2520.INC file.
At the end of the file you will find all of the settings. You want
_OSC_INTIO67_1H

[circuitpro]

Thanks Dave.

[circuitpro]

I have to use an external oscillator after all, because the internal is just not stable enough. I've got everything configured correctly (I think), but the first thing the program does, is turn on a LED. It's taking 25 SECONDS for this LED to come on!!

I've checked the datasheet, and power-on delays can be because of PWRTEN being set to 0, (which it isn't), or OST, but that isn't suppose to apply with external oscillators. So... what could be the problem?

My PBP 18F2520.INC file is below.


;************************************************* ***************
;* 18F2520.INC *
;* *
;* By : Leonard Zerman, Jeff Schmoyer *
;* Notice : Copyright (c) 2010 microEngineering Labs, Inc. *
;* All Rights Reserved *
;* Date : 05/21/10 *
;* Version : 2.60a *
;* Notes : *
;************************************************* ***************
NOLIST
ifdef PM_USED
LIST
"Error: PM does not support this device. Use MPASM."
NOLIST
else
LIST
LIST p = 18F2520, r = dec, w = -311, w = -230, f = inhx32
INCLUDE "P18F2520.INC" ; MPASM Header
__CONFIG _CONFIG1H, _OSC_ECIO6_1H & _FCMEN_OFF_1H & _IESO_OFF_1H
__CONFIG _CONFIG2L, _PWRT_OFF_2L & _BOREN_ON_2L & _BORV_0_2L
__CONFIG _CONFIG2H, _WDT_ON_2H & _WDTPS_512_2H
__CONFIG _CONFIG3H, _CCP2MX_PORTC_3H & _PBADEN_OFF_3H & _LPT1OSC_OFF_3H & _MCLRE_ON_3H
__CONFIG _CONFIG4L, _STVREN_ON_4L & _LVP_OFF_4L & _XINST_OFF_4L
NOLIST
endif
LIST
EEPROM_START EQU 0F00000h
BLOCK_SIZE EQU 32

Thanks for any pointers.

Len

[mackrackit]

_OSC_RCIO6_1H
Is not what you want
Try this
__CONFIG _CONFIG1H, _OSC_HS_1H & _FCMEN_OFF_1H & _IESO_OFF_1H

Then in your code
DEFINE OSC ??
?? being the speed of your external

[circuitpro]

The datasheet for the PIC18F2520 shows "ECIO" for "external clock with IO on RA6, and the P18F2520.INC file in MPASM sort of modified that to "_OSC_ECIO6_1H", so that's what I used. Using "_OSC_HS_1H", works, but gives me the same 25 second wait at power-up. I'm not using a crystal, I'm using an external oscillator/clock.

[mackrackit]

What exactly are you using for a clock? Is it running?
What is the speed?
Do you have DEFINE OSC xx in your code?

[mackrackit]

Once it finally starts does it run correctly?

[circuitpro]

Yes, it does. Regarding the EC settings, I tried using "_OSC_EC_1H", and did verify that I was getting 5 MHz (1/4 freq), out on A6. I'll be glad when this "CONFIG WIZARD" is working. :)

[circuitpro]

I didn't see your other questions... I'm using an external 20 MHz oscillator., and "DEFINE OSC 20" is in my code. I didn't have any trouble setting EITHER HS or EC settings (wierd), but it's the power-up delay that's confusing. Don't see a reason for it.

[mackrackit]

HS should be it. OSC input on both OSC pins.

What about MCLR?
Is it pulled high?

Since the time-outs occur from the POR pulse, if MCLR
is kept low long enough, all time-outs will expire. Bringing
MCLR high will begin execution immediately
(Figure 4-5). This is useful for testing purposes or to
synchronize more than one PIC18FXXXX device
operating in parallel.

[circuitpro]

I don't know why HS should be it. EC should be it. I'm using an External OSC. Input is only on pin A7. MCLR is pulled high w/ 4.7K, and snaps high immediately on power up.

[mackrackit]

When you said you were not using a crystal I got to thinking resonator.:o
You can use HS mode, OSC2 will just be an open pin.

As for your problem I am at a loss.
Maybe there is something at the beginning of your code messing things up?

[circuitpro]

This is my entire program, and I get a 25 sec. delay until the LED goes on.



ASM
;PORT A
CLRF PORTA
MOVLW 07h
MOVWF ADCON1 ;A/D'S OFF
MOVWF 07h
MOVWF CMCON ;COMPARATORS OFF
MOVLW 00000000b ;PIN DIRECTION PORT A
MOVWF TRISA
ENDASM

DEFINE OSC 20
LOW PORTA.6 'TURN LED ON
STOP




Thanks anyway, Dave!