Slave mode(GSM, Manual/Auto)

#include <mega32a.h>
#include <delay.h>
#include <stdio.h>
#include <stdlib.h>
#include <spi.h>
#define MAX             10
#define MAXANGLE        1999
#define MINANGLE        999
#define MOTOR_PLUS      0x01
#define MOTOR_MINUS     0x02
#define REMOTE_MOTOR    0x03
unsigned int dump_mode1 = 1; //this dump variable is to keep synchronization with master
unsigned int dump_mode2 = 1; //this dump variable is to keep synchronization with master
unsigned int dump_mode3 = 1; //this dump variable is to keep synchronization with master
unsigned int dump_mode4 = 1; //this dump variable is to keep synchronization with master
// SPI interrupt service routine
interrupt [SPI_STC] void spi_isr(void)
{
    unsigned char data;
    data = SPDR;
    if(data == MOTOR_PLUS) // condition used for Auto/Manual mode
    {
        if(OCR1A <= MAXANGLE)
        {
            OCR1A++;
            PORTD ^= 1 << PIND7;
        }
    }
    else if(data == MOTOR_MINUS) // condition used for Auto/Manual mode
    {
        if(OCR1A >= MINANGLE)
        {
            OCR1A--;
            PORTD ^= 1 << PIND7;
        }
    }
    else
    {
        OCR1A = data * 10; //returning the value back to the PWM range values then assign it to OCR1A
        PORTD ^= 1 << PIND7;
    }
}

// Declare your global variables here
void init()
{
    PORTA=0x00;
    DDRA=0x00;
    PORTB=0x00;
    DDRB=0x40;
    PORTC=0x00;
    DDRC=0x00;
    PORTD=0x00;
    DDRD=0xA0;

    TCCR1A=0b10000010;
    TCCR1B=0b00011001;
    ICR1H=0x4E;
    ICR1L=0x1F;
    OCR1A = 1499;

	TIMSK=0x00;

	ACSR=0x80;
	SFIOR=0x00;

	SPCR=0xC0;
	SPSR=0x00;
}
void main(void)
{
    // Clear the SPI interrupt flag
    #asm
        in   r30,spsr
        in   r30,spdr
    #endasm
    // Global enable interrupts
    #asm("sei")
    init();
    while (1)
    {
        // Place your code here
    }
}