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nurquhar
Joined: 05 Aug 2006
Posts: 149
Location: Redditch, UK
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| setting up clock from 18F67J10 |
 Posted: Wed Feb 06, 2008 12:25 pm |
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Whats the correct way to setup the PLL x 4 clock so I get 40Mhz system ? I am using PCH 3.249 and I have the the OSC1/2 pins hooked up to a 10Mhz xtal. The following code seems to run the PIC correctly at 10Mhz as I see the correct chars on serial port. How do I enable the PLL x 4 using CCS ? I have looked the following section in the header but I am none the wiser !
Whats in the header :
| Code: | ////////////////////////////////////////////////////////////////// INTERNAL RC
// Constants used in setup_oscillator() are:
#define OSC_INTRC 3
#define OSC_NORMAL 2
#define OSC_TIMER1 1
#define OSC_IDLE_ON_SLEEP 0x80
// Result may be (ignore all other bits)
#define OSC_STATE_EXT_RUNNING 8
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My Code :
| Code: | #include <18F67J10.h>
#use delay(clock=10000000)
#fuses H4_SW,NOXINST,NOWDT,NOPROTECT,NOFCMEN,CCP2C1
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7,enable=PIN_C0)
void main()
{
while(1) {
putc('a') ;
}
}
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Feb 06, 2008 5:09 pm |
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The .H file for vs. 4.066 looks like this:
| Quote: | // Constants used in setup_oscillator() are:
#define OSC_PLL_ON 0x4000
#define OSC_PLL_OFF 0
#define OSC_INTRC 3
#define OSC_NORMAL 2
#define OSC_TIMER1 1
#define OSC_IDLE_ON_SLEEP 0x80
// Result may be (ignore all other bits)
#define OSC_STATE_EXT_RUNNING 8 |
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nurquhar
Joined: 05 Aug 2006
Posts: 149
Location: Redditch, UK
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| Posted: Thu Feb 07, 2008 1:46 am |
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Dear PCM
Your a star, thanks for the "un-documented" info. I have corrected my code as follows and program now sends the correct chars when delay is set to 40Mhz.
| Code: | // Constants used in setup_oscillator() are:
#define OSC_PLL_ON 0x4000
#define OSC_PLL_OFF 0
#include <18F67J10.h>
#use delay(clock=40000000)
#fuses H4_SW,NOXINST,NOWDT,NOPROTECT,NOFCMEN,CCP2C1
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7,enable=PIN_C0)
void main()
{
setup_oscillator(OSC_PLL_ON) ;
while(1) {
putc('a') ;
}
}
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