Interrupts using PIC18f46k20 microcontroller

Question

I am new fairly new to C++ and i'm having problems Initializing the required resisters needed for my project on motor speed control. I have used the data sheet(link below) but cannot get around the problem PIC_datasheet

The two problems I am encountering

• interrupts not occurring. Code for interrupts process is below

• when I enable global interrupts i.e. 'INCONbits.GIE =1' nothing displays on the pic (leds and screen) as if it where in sleep mode.

Initialization.

    void InitializeSystem(void)
   {

OSCCON = 0b01110000;
OSCTUNEbits.PLLEN = 0;                  // turn off the PLL

// Setup I/O Ports.

ANSEL = 0x00;                          // all digital   check if needed*
TRISA = 0;                              // TRISA outputs
LATA = 0b11110000;                      // drive PORTA pins low

oled_res = 1;                           // do not reset LCD yet
oled_cs = 1;                            // do not select the LCD

TRISB = 0b11111111;


LATC = 0b00101000;
TRISC = 0b00000000;

TRISD = 0;                              // TRISD is LED output
LATD = 0;                               // turn off LEDS

TRISE = 0b00000111;



//configure buttons
WPUB = 0b00001111;
INTCON2bits.RBPU = 0;                   // turn on weak pull ups for RB0-RB3

INTCONbits.INT0IF = 0;                  // clear RB0 INT
INTCONbits.INT0IE = 1;                  // enable RB0 INT
INTCON2bits.INTEDG0 = 0;                // interrupt on falling edge 

INTCON3bits.INT1IF = 0;                 // clear RB1 INT
INTCON3bits.INT1IE = 1;                 // enable RB1 INT   
INTCON2bits.INTEDG1 = 0;                // interrupt on falling edge


INTCON3bits.INT2IF = 0;                 // clear RB2 INT
INTCON3bits.INT2IE = 1;                 // enable RB2 INT
INTCON2bits.INTEDG2 = 0;                // interrupt on falling edge




// Setup TMR0
T0CON = 0b00000010;          // 16- bit prescaller 1:8
INTCONbits.TMR0IE=1;
INTCONbits.TMR0IF=0;
INTCON2bits.TMR0IP=0;

// Configure Timer 1
T1CON   = 0b11111101;



// Configure MSSP for SPI master mode
SSPCON1 = 0b00110010;                   // clock idle high, Clk /64

SSPSTAT = 0b00000000;

PIR1bits.TMR1IF = 0; 
PIE1bits.TMR1IE = 1; 



OSCCON = 0b01110000;
OSCTUNEbits.PLLEN = 1;  // Puts the PIC at 64MHz
CCP1CON = 0b00001100;
PSTRCON = 0b00010001;

   // setup timer 2 for pwm
   T2CON = 0b00000111;// Prescale = 1:16, timer on, postscale not used with CCP module
PR2 = 255;     // Configure the Timer2 period
TRISCbits.TRISC2  = 0;              // Make CCP1 pin as output
CCP1CON = 0x0C;           // Configure CCP1 module in PWM mode
T2CON = 0x01;             // Set Prescaler to be 4, hence PWM frequency is set to   4.88KHz.
T2CON |= 0x04;            // Enable the Timer2, hence enable the PWM.
SetPWMDutyCycle(pwm);       // Intialize the PWM to 0.5 duty cycle

// Set up global interrupts
IOCB = 1;   
  RCONbits.IPEN = 1;                    // Enable priority levels on   interrupts
INTCONbits.RBIE = 1;
INTCONbits.RBIF = 0;
 INTCONbits.GIE = 1;

 T0CONbits.TMR0ON = 1;   // START TIMER0


} // end InitializeSystem
void SetPWMDutyCycle(unsigned int DutyCycle)      // Give a value in between 0 and      1024 for DutyCycle
{
CCPR1L   = DutyCycle>>2;            // Put MSB 8 bits in CCPR1L
CCP1CON &= 0xCF;                    // Make bit4 and 5 zero
CCP1CON |= (0x30&(DutyCycle<<4));   // Assign Last 2 LSBs to CCP1CON
}

Interrupt Service

#pragma code InterruptVectorLow = 0x18
void InterruptVectorLow (void)
{
  _asm  
     goto InterruptServiceLow //jump to interrupt routine
  _endasm
}

//----------Interrupt Service Routine-------------------------------------
#pragma interrupt InterruptServiceHigh
void InterruptServiceHigh(void)
{

if(INTCONbits.RBIF)
{
    INTCONbits.RBIF = 0;

    if(PORTBbits.RB6!=0)                                         
        {
            UpperCounter++; //increment UpperCounter if RB6 goes high                           
            speed_counter++; // increment the counter used to calculate  
                                              //speed                                               
            LATDbits.LATD7=~LATDbits.LATD7;  // LED7 changes state each   
                                                             //rising edge                      
            Delay10TCYx(1);         
        }



   else if(PORTBbits.RB7!=0)    
             //count pulses from ch B                                       
        {
            LowerCounter++; //increment LowerCounter if RB7 goes high                                                                    
            speed_counter++;                                    
                    LATDbits.LATD0=~LATDbits.LATD0; //LED0 changes state each  
                                                            //rising edge                   
            Delay10TCYx(1);             
        }



     else if(PORTBbits.RB5 != 0)
                   //count pulses from ch Z                                                                   
        {
            LowerCounter=0;  //reset LowerCounter                           
                    UpperCounter=0;   //reset UpperCounter                          
            Delay10TCYx(1);             
        }
}
}

#pragma interruptlow InterruptServiceLow// "interruptlow" pragma for low priority
void InterruptServiceLow(void)
{

if(INTCONbits.TMR0IF)
       {
    position2=speed_counter;                                            

    speed=((((position2-position1)/64)*60)/2.1);        
        //calculate speed. TMR0 on 16bit prescalar1:8     
    TMR0H = 0;    
            //  clear timer - always write upper byte first                                        
    TMR0L = 0;
            INTCONbits.TMR0IF = 0;    
             // clear (reset) flag                                   
    LATDbits.LATD2=~LATDbits.LATD2;
    position1=speed_counter;
 }
}