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rudy
Joined: 27 Apr 2008
Posts: 168
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| 18F4550 don't start, why? |
 Posted: Sat Apr 03, 2010 3:19 pm |
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Hi all,
I am changing one slave 16F877A for a new 18F4550. I tried everything to put the processor to start, but no deal, anybody can help me?
I use 20MHz crystal, and I need to run the chip as faster as possible. I don't use USB in my application.
Here are the fuses, I think the problem is here.
| Code: |
#fuses HSPLL,USBDIV,PLL5,CPUDIV1,VREGEN,NOWDT,NOPROTECT,NOLVP,NODEBUG
#use delay(clock=48000000)
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Best regards. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Sat Apr 03, 2010 9:59 pm |
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| Quote: |
I use 20MHz crystal.
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First try blinking an LED with the PIC running at 20 MHz, as shown in
the program below. Does this work ?
| Code: |
#include <18F4550.h>
#fuses HS, NOWDT, PUT, BROWNOUT, NOLVP
#use delay(clock=20000000)
//====================================
void main()
{
// Blink an LED on pin B0.
while(1)
{
output_high(PIN_B0);
delay_ms(500);
output_low(PIN_B0);
delay_ms(500);
}
}
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If that works, change the fuses to run in PLL mode:
| Code: |
#include <18F4550.h>
#fuses HSPLL,NOWDT,NOPROTECT,NOLVP,USBDIV,PLL5,CPUDIV1
#use delay(clock=48000000)
//==========================
void main()
{
while(1)
{
output_high(PIN_B0);
delay_ms(500);
output_low(PIN_B0);
delay_ms(500);
}
} |
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rudy
Joined: 27 Apr 2008
Posts: 168
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| Posted: Sun Apr 04, 2010 5:59 am |
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Yes, the problem was the port address, I was calling 0x80 but, in 18F4550 is 0xf80.
works fine now,
regards. |
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