//#include <p18cxxx.h>
#include <p18f14k50.h>
#include <stdio.h>
#include <math.h>
#include <delays.h>
#include "i2c.h"

#pragma config FOSC = HS
#pragma config PLLEN = ON
#pragma config CPUDIV = CLKDIV4
#pragma config USBDIV = OFF
#pragma config WDTEN = OFF
#pragma config MCLRE = ON
#pragma config IESO = OFF
#pragma config HFOFST = OFF
#pragma config XINST = OFF

#define MAX_FDCO_FREQ 5670.0
#define MIN_FDCO_FREQ 4850.0
#define FXTAL 114.327438




void write_si570_regs (float RFREQ, unsigned char HS_DIV, unsigned char N1);
void prog_si570 (float FOUT);

void main (void)
{
	float FOUT;
        unsigned char delay=25;
        TRISC=0b00000000; /*RC0-RC7 salidas*/
        TRISB=0b11110000;/*RB6=SCL, RB4=SDA, RB7=RB5=INPUTs*/
        WPUB= 0b10100000;/*RB7, RB5, WEAK PULLUP ENABLED*/
        WDTCON=0x00;/*DESHABILITAR WATCHDOG*/
        INTCON2=0b01110101;
        ANSELH=0x00;
        PORTC=0x00;/*reset del puerto C*/

        FOUT=14.000000;
	prog_si570 (FOUT);

        while(1)
        {
            if (PORTBbits.RB7==0)
            {
             FOUT=FOUT+0.025;
             prog_si570(FOUT);
             Delay10KTCYx(delay);
            }
                        
            if (PORTBbits.RB5==0)
            {
             FOUT=FOUT-0.025;
             prog_si570(FOUT);
             Delay10KTCYx(delay);
            }

        }





}


void prog_si570 (float FOUT)
{
	float RFREQ;
	float FDCO;
	unsigned char HS_DIV;
	unsigned char N1 = 1;

	for (HS_DIV = 11; HS_DIV >= 7; HS_DIV -= 2)
	{
		FDCO=FOUT * HS_DIV*N1;
		if ( (FDCO <= MAX_FDCO_FREQ) && (FDCO >= MIN_FDCO_FREQ) )
		{
			RFREQ=(FDCO)/FXTAL;
			write_si570_regs (RFREQ, HS_DIV, N1);
			return;
		}
	}

	for (HS_DIV = 6; HS_DIV >= 4; HS_DIV--)
	{
		FDCO=FOUT * HS_DIV*N1;
		if ( (FDCO <= MAX_FDCO_FREQ) && (FDCO >= MIN_FDCO_FREQ) )
		{
			RFREQ=(FDCO)/FXTAL;
			write_si570_regs (RFREQ, HS_DIV, N1);
			return;
		}
	}


	for (N1 = 2; N1 <= 128; N1 += 2)
	{
		for (HS_DIV = 11; HS_DIV >= 7; HS_DIV -= 2)
		{
			FDCO=FOUT * HS_DIV*N1;
			if ( (FDCO <= MAX_FDCO_FREQ) && (FDCO >= MIN_FDCO_FREQ) )
			{
				RFREQ=(FDCO)/FXTAL;
				write_si570_regs (RFREQ, HS_DIV, N1);
				return;
			}
		}

		for (HS_DIV = 6; HS_DIV >= 4; HS_DIV--)
		{
			FDCO=FOUT * HS_DIV*N1;
			if ( (FDCO <= MAX_FDCO_FREQ) && (FDCO >= MIN_FDCO_FREQ) )
			{
				RFREQ=(FDCO)/FXTAL;
				write_si570_regs (RFREQ, HS_DIV, N1);
				return;
			}
		}
	}

	return;
}

void write_si570_regs (float RFREQ, unsigned char HS_DIV, unsigned char N1)

{
unsigned char Si570_REG_7;
unsigned char Si570_REG_8;
unsigned char Si570_REG_9;
unsigned char Si570_REG_10;
unsigned char Si570_REG_11;
unsigned char Si570_REG_12;
unsigned char Si570_REG_135;
unsigned char Si570_REG_137;

unsigned int entera_de_RFREQ;
float decimal_de_RFREQ;
unsigned long resto;

unsigned char sync_mode;
unsigned char slew;
unsigned char add1;
unsigned char w;
unsigned char data;
unsigned char status;

Si570_REG_7=((HS_DIV-4) << 5) | ((N1-1) >> 2);
entera_de_RFREQ = floor(RFREQ);
Si570_REG_8= (((N1-1) << 6 ) | (entera_de_RFREQ >> 4));
decimal_de_RFREQ=RFREQ-entera_de_RFREQ;
resto=floor(decimal_de_RFREQ *268435456);
Si570_REG_9=((entera_de_RFREQ << 4) | (resto >> 24));
Si570_REG_10=(resto >> 16);
Si570_REG_11=(resto >> 8);
Si570_REG_12=(resto);

sync_mode=MASTER;
slew=SLEW_OFF;
add1=0xAA;                              //Si-570 address 0x55*2

OpenI2C(sync_mode, slew);
SSPADD=0x1D;                            //100kHz SCL clock @ 12 MHz

    IdleI2C();                          //read 137 register for DCO freezze
StartI2C();
    IdleI2C();
WriteI2C( add1 | 0x00 );
    IdleI2C();
WriteI2C((unsigned char) 137 );
    IdleI2C();
RestartI2C();
    IdleI2C();
WriteI2C( add1 | 0x01 );
    IdleI2C();
Si570_REG_137=ReadI2C();
    IdleI2C();
NotAckI2C();
    IdleI2C();
StopI2C();

Si570_REG_137=(Si570_REG_137 | 0x10);   //set bit 4 of 137 reg to freezze DCO
 
    IdleI2C();                          //write 137 register
StartI2C();
    IdleI2C();
WriteI2C( add1 | 0x00 );
    IdleI2C();
WriteI2C( (unsigned char)137 );
    IdleI2C();
WriteI2C(Si570_REG_137);
    IdleI2C();
StopI2C();


    IdleI2C();                          //write 7 register
StartI2C();
    IdleI2C();
WriteI2C( add1 | 0x00 );
    IdleI2C();
WriteI2C( (unsigned char) 7 );  
    IdleI2C();
WriteI2C(Si570_REG_7);
    IdleI2C();
StopI2C();


    IdleI2C();                          //write 8 register
StartI2C();
    IdleI2C();
WriteI2C( add1 | 0x00 );
    IdleI2C();
WriteI2C( (unsigned char) 8 );
    IdleI2C();
WriteI2C(Si570_REG_8);
    IdleI2C();
StopI2C();

    IdleI2C();                          //write 9 register
StartI2C();
    IdleI2C();
WriteI2C( add1 | 0x00 );
    IdleI2C();
WriteI2C( (unsigned char) 9 );
    IdleI2C();
WriteI2C(Si570_REG_9);
    IdleI2C();
StopI2C();

    IdleI2C();                          //write 10 register
StartI2C();
    IdleI2C();
WriteI2C( add1 | 0x00 );
    IdleI2C();
WriteI2C( (unsigned char) 10 );
    IdleI2C();
WriteI2C(Si570_REG_10);
    IdleI2C();
StopI2C();


    IdleI2C();                          //write 11 register
StartI2C();
    IdleI2C();
WriteI2C( add1 | 0x00 );
    IdleI2C();
WriteI2C( (unsigned char) 11 );
    IdleI2C();
WriteI2C(Si570_REG_11);
    IdleI2C();
StopI2C();

    IdleI2C();                          //write 12 register
StartI2C();
    IdleI2C();
WriteI2C( add1 | 0x00 );
    IdleI2C();
WriteI2C( (unsigned char) 12);
    IdleI2C();
WriteI2C(Si570_REG_12);
    IdleI2C();
StopI2C();

    IdleI2C();                          //read 137 register for DCO unfreezze
StartI2C();
    IdleI2C();
WriteI2C( add1 | 0x00 );
    IdleI2C();
WriteI2C( (unsigned char)137 );
    IdleI2C();
RestartI2C();
    IdleI2C();
WriteI2C( add1 | 0x01 );
    IdleI2C();
Si570_REG_137=ReadI2C();
    IdleI2C();
NotAckI2C();
    IdleI2C();
StopI2C();

Si570_REG_137=(Si570_REG_137 & 0xEF); //clear bit 4 of 137 reg to freezze DCO

    IdleI2C();
StartI2C();
    IdleI2C();
WriteI2C( add1 | 0x00 );
    IdleI2C();
WriteI2C( (unsigned char)137 );
    IdleI2C();
WriteI2C(Si570_REG_137);
    IdleI2C();
StopI2C();

    IdleI2C();
StartI2C();
    IdleI2C();
WriteI2C( add1 | 0x00 );
    IdleI2C();
WriteI2C( (unsigned char)135 ); // set bit 6 of 135 register for NewFreq to be applied
    IdleI2C();
WriteI2C( (unsigned char) 0x40 );
    IdleI2C();
StopI2C();




return;
}