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buttlumpy
Joined: 23 Aug 2006
Posts: 1
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| Help with I/O on A6 & A7 on 18F4580 |
 Posted: Wed Aug 23, 2006 4:19 pm |
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I need to use all of port A on the 18F4580 for output, and want to use the internal oscillator.
I've been trying to get the fuses and settings right to do this, but I always have trouble when setting the A6 pin. In the data sheet, it lists the oscillator configuration I want as INTIO2, but the only fuses listed for the device in PICC that seem germane are INTRC_IO. I currently have this fuse set.
It really seems that I am stuck in the INTIO1 mode as described in the datasheet. I'm not sure what to do to get full I/O functionality on both A6 and A7. I'm not sure how to manually set the OSCCON register, or even what to set it too.
Any help would be greatly appreciated. Thanks! |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Aug 23, 2006 4:39 pm |
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What is your compiler version ? For PCH vs. 3.249, If I compile the
program shown below, I get these fuse settings at the end of the .LST file:
| Code: |
Configuration Fuses:
Word 1: 0800 NOIESO NOFCMEN INTRC_IO RESERVED
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This shows that the Config 1H byte is set to 0x08. The 18F4580 data
sheet shows this setting allows digital i/o on RA6 and RA7:
| Quote: |
CONFIG1H: CONFIGURATION REGISTER 1 HIGH (BYTE ADDRESS 300001h)
bit 3-0 FOSC3:FOSC0: Oscillator Selection bits
11xx = External RC oscillator, CLKO function on RA6
101x = External RC oscillator, CLKO function on RA6
1001 = Internal oscillator block, CLKO function on RA6, port function on RA7
1000 = Internal oscillator block, port function on RA6 and RA7
0111 = External RC oscillator, port function on RA6
0110 = HS oscillator, PLL enabled (Clock Frequency = 4 x FOSC1)
0101 = EC oscillator, port function on RA6
0100 = EC oscillator, CLKO function on RA6
0011 = External RC oscillator, CLKO function on RA6
0010 = HS oscillator
0001 = XT oscillator
0000 = LP oscillator |
| Code: |
#include <18F4580.h>
#fuses INTRC_IO,NOWDT,NOPROTECT,BROWNOUT,PUT,NOLVP
#use delay(clock=8000000)
//===========================
void main()
{
while(1)
{
output_high(PIN_A6);
output_high(PIN_A7);
delay_ms(500);
output_low(PIN_A6);
output_low(PIN_A7);
delay_ms(500);
}
} |
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