/*
*************SOURCE FILE********************
File saved as       main.c
Compiler:           XC8 v1.38
CCI compliant?      Yes
Software function   Si5351a i2c programmer utilizing the Silabs 'Clockbuilder' generated .h file
Written by          Russell E. Tribe
Date                8/10/2016
For (PIC type)      PIC16F1459
Resonator           Internal 16Mhz
CPU clock           16MHZ (48 MHz PLL output divided by 3 in CPU divider)
Instruction clock   4MHz  T = 0.25µS (4MIPS)
Other information   Other information   LED on pin2  (RA5)
                    SDA on pin 13 (RB4)
                    SCL on pin 11 (RB6)
                    ********* 
                    NB:  Follow instructions in the file 'register_map.h'
                    *********
*/

/** C O N F I G U R A T I O N   B I T S ******************************/
// CONFIG1
#pragma config FOSC = INTOSC    // Oscillator Selection Bits (INTOSC oscillator: I/O function on CLKIN pin)
#pragma config WDTE = OFF       // Watchdog Timer Enable (WDT disabled)
#pragma config PWRTE = OFF      // Power-up Timer Enable (PWRT disabled)
#pragma config MCLRE = OFF      // MCLR Pin Function Select (MCLR/VPP pin function is digital input)
#pragma config CP = OFF         // Flash Program Memory Code Protection (Program memory code protection is disabled)
#pragma config BOREN = OFF      // Brown-out Reset Enable (Brown-out Reset disabled)
#pragma config CLKOUTEN = OFF   // Clock Out Enable (CLKOUT function is disabled. I/O or oscillator function on the CLKOUT pin)
#pragma config IESO = OFF       // Internal/External Switchover Mode (Internal/External Switchover Mode is disabled)
#pragma config FCMEN = OFF      // Fail-Safe Clock Monitor Enable (Fail-Safe Clock Monitor is disabled)

// CONFIG2
#pragma config WRT = OFF        // Flash Memory Self-Write Protection (Write protection off)
#pragma config CPUDIV = CLKDIV3 // CPU System Clock Selection Bit (divide by 3 = 16Mhz)
#pragma config USBLSCLK = 48MHz // USB Low SPeed Clock Selection bit (System clock expects 48 MHz, FS/LS USB CLKENs divide-by is set to 8.)
#pragma config PLLMULT = 3x     // PLL Multipler Selection Bit (3x Output Frequency Selected)
#pragma config PLLEN = ENABLED  // PLL Enable Bit (3x or 4x PLL is enabled - see above)
#pragma config STVREN = OFF     // Stack Overflow/Underflow Reset Enable (Stack Overflow or Underflow will not cause a Reset)
#pragma config BORV = LO        // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (Vbor), low trip point selected.)
#pragma config LPBOR = OFF      // Low-Power Brown Out Reset (Low-Power BOR is disabled)
#pragma config LVP = OFF        // Low-Voltage Programming Enable (High-voltage on MCLR/VPP must be used for programming)

/** I N C L U D E S **************************************************/
#include <xc.h>             //Provides PIC header file and is required for CCI compliance
#include "i2c.h"
#include "register_map.h"   //This is the data generated by Silabs 'Clockbuilder'

/** FUNCTION PROTOTYPES **********************************************/
void intialSetUp (void);    //Manages the initialization of all PIC functions
void programSi5351a (void);
void sendRegister (unsigned char, unsigned char);
void wait (unsigned char);
void flashLED (unsigned char);

/** DECLARATIONS******************************************************/
#define _XTAL_FREQ 16000000     //Used by library delay routines AND i2c baud setting

#define LED LATAbits.LATA5      //Pin 2
#define OFF 0
#define ON 1

#define BAUD_RATE 100000        //Speed of I2C clock - either 100kHz ('Standard Speed') or 400 kHz ('High Speed')
#define SI5351A_ADDRESS 0xC0

/** GLOBAL VARIABLES *************************************************/

//****************************************
int main(void)
{
    unsigned char sync_mode, slew;
    
    intialSetUp ();     //Initializes the PIC
    flashLED (1);       //Say "Hi!"
    __delay_ms(50);     //Allow time for the si5351a to initialize

//Initialize the I2C module for MASTER mode with 100kHz clock    
    CloseI2C();         //Close i2c if it was operating earlier   
    sync_mode = MASTER;
    slew = SLEW_OFF;
    SSP1ADD = (_XTAL_FREQ/(4*BAUD_RATE))-1;     //Determines speed of the I2C bus - using this formula instead of entering a number
                                                //is convenient when changing oscillator speed eg when migrating to a different PIC
    OpenI2C(sync_mode,slew);
               
    programSi5351a ();

//Terminate communication from MASTER side
    CloseI2C();         //Close I2C module
    
    flashLED (2);       //Say "Goodbye!"
    SLEEP ();           //Shut down the PIC in order to prevent RFI and to save power
    while(1);           //Wait here - end of program
} //main

//****************************************
void intialSetUp (void)
{
/* Firstly, set up the oscillator.  (I have kept the settings I used for an earlier USB project)
These oscillator settings are required for FS USB operation
and will deliver a 16MHz system clock
*/
    OSCCONbits.SCS = 0b00;      //Clock source determined in Config words
    OSCCONbits.IRCF = 0b1111;   //16Mhz internal oscillator frequency selected
    OSCCONbits.SPLLMULT = 1;    //PLL x 3 selected
    
    while (OSCSTATbits.HFIOFS == 0);    //Wait until int osc is stable to 5%
    
    ACTCONbits.ACTSRC = 1;      //Active tuning derived from FS USB
    ACTCONbits.ACTEN = 1;       //Active clock tuning is enabled
    
    //Cannot use this next line until a USB connection has been made!
    //while (ACTCONbits.ACTLOCK == 0);    //Wait until active tuning is locked
    
    ANSELBbits.ANSB4 = 0;       //Select digital mode for the SDA pin (Pin 13)
    WPUBbits.WPUB4 = 0;
    WPUBbits.WPUB6 = 0;
    
    //Set up pin 2 (RA5) as the LED output
    TRISAbits.TRISA5 = 0;       //Pin 2 (RA3) is an output pin
    LED = OFF;
}

//****************************************
//The si5351a requires re-programming at every power-up
//Refer to Silabs Si5251a data sheet section 5.1 and figure 12 for i2c Programming Procedure.
//Refer to Silabs AN619 for register details
void programSi5351a (void)
{
    unsigned char counter;
    Reg_Data current;
    
//The following procedures comply with Silabs Si5251a data sheet section 5.1 and
//figure 12 for i2c Programming Procedure.
    sendRegister (3,0xFF);      //Disable outputs
    sendRegister (16,0x80);     //Power down output drivers
    sendRegister (17,0x80);     //Power down output drivers     
    sendRegister (18,0x80);     //Power down output drivers
    sendRegister (19,0x80);     //Power down output drivers
    sendRegister (20,0x80);     //Power down output drivers
    sendRegister (21,0x80);     //Power down output drivers
    sendRegister (22,0x80);     //Power down output drivers
    sendRegister (23,0x80);     //Power down output drivers
    
//Now send the register data from register_map.h
    for(counter = 0; counter < NUM_REGS_MAX; counter++)
    {
        current = Reg_Store[counter];
        sendRegister (current.Reg_Addr, current.Reg_Val);
    }
    
    sendRegister (177,0xAC);     //Apply PLLA and PLLB soft reset
    sendRegister (3,0xFE);       //Enable Channel 0.  Others disabled   
}

//****************************************
/*This function follows the description in Silabs Si5251a data sheet section 4
in particular, figure 9 for i2c write operation.  NB 'Burst Mode' writing cannot be
used as the required register addresses are not contiguous*/
void sendRegister (unsigned char reg, unsigned char data)
{
    StartI2C ();
	masterSendI2C (SI5351A_ADDRESS | 0x00);  //Sends si5351a address and 'write' bit
	masterSendI2C (reg);
    masterSendI2C (data);
    StopI2C ();
}

//****************************************
//A delay function
void wait (unsigned char iterations)
{
    while (iterations)
    {
        __delay_ms(100);
        iterations --;
    }
}

//****************************************
void flashLED (unsigned char iterations)
{
    while (iterations)
    {
        LED = ON;
        __delay_ms(500);
        LED = OFF;
        __delay_ms(500);
        iterations --;
    }
 }

//****************************************