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[mAnNaRo]
Joined: 02 Dec 2005
Posts: 28
Location: Italy, Milan
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| PIC18F46K20 vs CCS |
 Posted: Mon Dec 22, 2008 5:13 am |
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Hi All,
The PIC in object is not yet test by CCS :( and in fact I am experiencing some problems setting the clock speed. I need to use the internal oscillator.
The setting I use is:
| Code: |
#fuses INTRC,NOWDT,NOPROTECT,NOLVP,NODEBUG, noBROWNOUT
#use delay(clock=8000000)
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I use the same configuration (and same code) on PIC 18F2455 and it work. Using clock=8000000 or clock=4000000 I get the right speed (tested brutally with a delay instruction of 4seconds and a stopwatch and tested with serial communication, 9600bps set in program work with 9600bps set in hyperterminal).
On PIC18F46K20 I know a difference using clock=4000000 than clock=8000000 in code speed BUT THE DELAY INSTRUCTION of 4seconds always takes 2 seconds!!!! (both clock=8000000 and clock=4000000). Moreover an rs232 speed of 9600bps set in code work only with a 19200bps in hyper terminal!!
This is the strange behavior, knows someone help me?
Thanks
Alex |
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PICoHolic
Joined: 04 Jan 2005
Posts: 224
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| Posted: Mon Dec 22, 2008 6:32 am |
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You need to configure the internal osc using "setup_oscillator" function
For ex, to set for 31KHz:
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setup_oscillator(OSC_31KHZ|OSC_INTRC|OSC_IDLE_MODE|OSC_PLL_OFF);
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[mAnNaRo]
Joined: 02 Dec 2005
Posts: 28
Location: Italy, Milan
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| Posted: Mon Dec 22, 2008 8:46 am |
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I doesn't work :-(
This is my setup:
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setup_oscillator(OSC_8MHZ|OSC_INTRC|OSC_IDLE_MODE);
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the serial comunication set to 9600bps work always with a value of 19200bps in hyperterminal :-(
Alex |
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PICoHolic
Joined: 04 Jan 2005
Posts: 224
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| Posted: Mon Dec 22, 2008 9:31 am |
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| Plz post your code along with compiler version! |
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[mAnNaRo]
Joined: 02 Dec 2005
Posts: 28
Location: Italy, Milan
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| Posted: Mon Dec 22, 2008 10:21 am |
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Compiler version PCH 4.078.
| Code: |
#include <18F46K20.h>
#fuses INTRC_IO,NOWDT,NOPROTECT,NOLVP,NODEBUG, noBROWNOUT
#use delay(clock=8000000)
#use rs232(baud=9600, xmit=PIN_B7, rcv=PIN_B6)
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and a simple:
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printf("Battery connected!\r\n");
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Alex |
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Ttelmah
Guest
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| Posted: Mon Dec 22, 2008 4:06 pm |
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You need a simple program we can compile. As short as possible, but it needs the main, and the basic initialisation.
The problem could come from the layout of your program, hence we need to see this.
Best Wishes |
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[mAnNaRo]
Joined: 02 Dec 2005
Posts: 28
Location: Italy, Milan
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| Posted: Tue Dec 23, 2008 3:49 pm |
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| Code: |
#include <18F46K20.h>
#fuses INTRC_IO,NOWDT,NOPROTECT,NOLVP,NODEBUG, noBROWNOUT
#use delay(clock=8000000)
#use rs232(baud=9600, xmit=PIN_B7, rcv=PIN_B6)
void main(void)
{
int16 i;
delay_ms(2000);
printf("TEST UART SPEED\r\n");
i=0;
delay_ms(10000);
printf("10 seconds\r\n");
while(1)
{
for(i=0; i<0xFFFF;i++)
{
printf("%Lu\r\n", i);
}
}
}
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At 8Mhz (clock=8000000):
Hyperterminal work at 19200bps
The delay take about 5 seconds
At 4Mhz (clock=4000000):
Hyperterminal work at 19200bps
The delay take about 5 seconds
The speed of code executed do not change in 8 or 4 MHz.
Using MPLAB SIM the delay of 10 seconds take 4seconds (measured with mplab stopwatch)
Alex |
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Ttelmah
Guest
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| Posted: Tue Dec 23, 2008 4:03 pm |
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OK.
What is happening, is that the compiler is using the 4620 settings, not the 46K20 settings. The clock speed table for the 4620, goes:
31K
125K
250K
500K
1M
2M
4M
8M
While the one for the 46K20, goes:
31K
250K
500K
1M
2M
4M
8M
16M
Note the doubling.
You need to replace the clock setting lines in the include file with:
| Code: |
// Constants used in setup_oscillator() are:
// First param:
#define OSC_31KHZ 0
#define OSC_250KHZ 0x10
#define OSC_500KHZ 0x20
#define OSC_1MHZ 0x30
#define OSC_2MHZ 0x40
#define OSC_4MHZ 0x50
#define OSC_8MHZ 0x60
#define OSC_16MHZ 0x70
#define OSC_32MHZ 0x4060
#define OSC_64MHZ 0x4070
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and add the line:
setup_oscillator(OSC_8MHz);
at the start of the main (leave the delay statement set to 8MHz).
This should fix it.
Best Wishes |
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[mAnNaRo]
Joined: 02 Dec 2005
Posts: 28
Location: Italy, Milan
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| Posted: Wed Dec 24, 2008 12:15 pm |
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Thanks Ttelmah!!! Fix it! 
Alex |
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dyeatman
Joined: 06 Sep 2003
Posts: 1934
Location: Norman, OK
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| Posted: Wed Dec 24, 2008 1:00 pm |
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| Now CCS needs to be notified of the error in the H file... |
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[mAnNaRo]
Joined: 02 Dec 2005
Posts: 28
Location: Italy, Milan
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| Posted: Wed Dec 24, 2008 2:39 pm |
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...and someone with the last version of PCH should notify the bug in the compiler because the "setup_oscillator(OSC_8MHz);" instruction is a
way to get around the problem. 
Alex |
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Mr_T
Guest
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| problem of clk with pic18f46k20 |
| Posted: Wed May 06, 2009 8:31 am |
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Hi all !!!
i'm using a PIC18F46K20 and i have a problem with the clock.
i can't see the the CPU frequence. If you can help me plz, i want to know how can i see the FCPU ?
| Code: | /** I N C L U D E S **************************************************/
#include "p18f46k20.h"
#include "delays.h"
#include "09 IntOSC.h" // header file
#include "dhry_v11.h"
/** V A R I A B L E S *************************************************/
#pragma idata // declare statically allocated initialized variables
unsigned char LED_Count = 0; // 8-bit variable
IntOSCFreq ClockSpeed = C_125kHz;
/** D E C L A R A T I O N S *******************************************/
#pragma code // declare executable instructions
//#pragma config FOSC = INTIO67
void SetIntOSC(IntOSCFreq *ClockSet)
{
//{ // This function sets the internal oscillator to the frequency of
// // the ClockSet argument variable, and then increments ClockSet
// // to the next supported frequency.
OSCCON = 0b01110000; // IRCFx = 111 (16 MHz)
OSCTUNEbits.PLLEN = 1; // x4 PLL enabled = 64 MHz
//OSCCON = 0b01110000; // IRCFx = 111 (16 MHz)
//OSCTUNEbits.PLLEN = 0; // 16 MHz
//OSCCON = 0b01100000; // IRCFx = 110 (8 MHz)
//OSCTUNEbits.PLLEN = 1; // x4 PLL enabled = 32 MHz
}
void main (void)
{
// Init I/O
//CONFIG1H = 0b00001001;
TRISA = 0; // TRISA outputs
LATA = 0b00000000; // drive PORTA pins low
TRISD = 0x7F; // PORTD bits 7:0 are all outputs (0)
SetIntOSC(&ClockSpeed);
while (1)
{
LATDbits.LATD7 = ~LATDbits.LATD7; // toggle LATD
dhry_run();
// Delay1KTCYx(50); // delay 32,000 cycles or about 1 sec at 125kHz
}
} |
this is my code it's really simple. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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mr_T
Guest
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| Posted: Thu May 07, 2009 1:46 am |
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Thank you very much for the link. I have posted my questions on the microchip forum.(sorry for my english i'm not from england )
May be i can ask you some question ?
i'm doing dhristone test on one pic18f46k20 and i have a problem with array size.
Normaly on dhrystone test you use array=[20] and on this pic i use array=[8].
With array=[8] i can build my project but i lost a lot of information and that means the drystone test is totally wrong and means nothing.
May be you have already made a drystone test on one pic 18 ? |
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