PROBLEMS WITH #use delay(clock=4000000)

dax · Joined: 19 Jun 2005 Posts: 2

Hi

Im working with PIC18LF4620 with 4 MHz external clock.

my header is

#include <18F4620.h>
#device ICD=TRUE
#fuses NOWDT,XT,NOPUT
#use delay(clock=4000000)
#use rs232(DEBUGGER)

and the program never reach the main function, it remains at the #use delay(clock=4000000) line. The clock seems to work fine, my CCS compiler version its 3.224. If somebady knows abut this, all help its welcome,

thanks
_________________
dax

mickey231bhq · Joined: 06 Apr 2005 Posts: 19 Location: Formosa

XT????

rnielsen · Joined: 23 Sep 2003 Posts: 852 Location: Utah

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Many PIC data sheets recommend XT for 4 MHz operation.
Examples:
16F877
16F877A
16F628
16F628A
18F452
I have used XT mode at 4 MHz on most of the PICs above with no problem.

For newer PICs, the data sheets give the option of using XT or HS mode
for a 4 MHz crystal. Examples:
16F88
16F688
18F4620

I don't think using XT mode is causing his problem.
It's more likely that he needs to add NOLVP to the #fuses statement.
That might fix the problem.

Kit · Guest

#fuses NOWDT,XT,NOPUT

use
#fuses NOWDT,HS,NOPUT

or you can add
#fuses NOWDT,HS, NOPUT, NOLVP

I only manage to get my PIC run after adding NOLVP.

if you dont want to use MCLR
#fuses NOWDT,HS, NOPUT, NOLVP, NOMCLR (try this first)