Frequency measurement using input capture module in dspic30f5011

 unsigned int timePeriod;
 float freq = 0;
/************************** main function *********************************/
main()
{
	
	uart1_init();
	timer_init();
	IC_INIT();	
	while(1);	
}

/***********************Input Capture init function ***************************/
void IC_INIT(void)
{
	  
	IC2CONbits.ICM     = 0b010;				// Input Capture Mode Select (Every rising edge)
	IC2CONbits.ICBNE  =0;				// Input Capture Buffer Empty Status (Read Only)
	IC2CONbits.ICOV    =0;				// Input Capture Overflow Status Flag (Read Only)
	IC2CONbits.ICI       = 00;				// Select Number of Captures per Interrupt bits (00 = Interrupt on every capture event)
	IC2CONbits.ICTMR  =0;				// Input Capture Timer Select bits (0=TMR3 contents are captured on captured event)
	IC2CONbits.ICSIDL =0;    			// Input Capture Module Stop in Idle Control(0=Input capture module will continue to operate in CPU Idle mode)
	IPC1bits.IC2IP        = 5;	
	IFS0bits.IC2IF        = 0;       			// Input Capture Channel 2 Interrupt Flag Status )0=Interrupt bit is cleared
	IEC0bits.IC2IE        = 1;     			// Input Capture Channel 2 Interrupt Enable bit (1 = Interrupt request enabled) 
	
}

/***************** ISR function ***********************/
void __attribute__((__interrupt__,no_auto_psv)) _IC2Interrupt(void)
{
	timePeriod        =IC2BUF;	
	T3CONbits.TON	= OFF;							// disable timer3
	TMR3		= 0X0000;						// TIMER3 REGISTER
	T3CONbits.TON	= ON;							// enable timer3
	count++;
	if(count == 2)
	{			
		timePeriod = current_value; 
		freq = (float)(8000000/timePeriod);			// 8Mhz is my operating frequency
		printf("freq =%f\n",(double)freq);	
		count = 0;
	}
	IFS0bits.IC2IF= 0; //Clear bit IC1IF (IFS<2>)

}


/************************* Timer3 init funct ***************************/
void timer_init(void)
{
 
	T3CON			= 0;					//desabling timer3
	TMR3			= 0X0000;				// TIMER3 REGISTER
	PR3			        = 0xffff;				// time period  maximum value 
	T3CONbits.TSIDL	= 0;					// configuring timer3
	T3CONbits.TCKPS	= 0b00;	                 	// 1:1 prescaler						
	IFS0bits.T3IF		= 0;					// clear interrupt flag 
	IPC1bits.T3IP		= 7;					// set interrupt priority
	IEC0bits.T3IE		= 1;					// interrupt enable
	T3CONbits.TON		= ON;				// enable timer3
	
	
}


void __attribute__((__interrupt__,no_auto_psv)) _T3Interrupt(void)
{
	IFS0bits.T3IF	= 0;
}

void __attribute__((__interrupt__,no_auto_psv)) _IC2Interrupt(void)
{
	
	current_value=IC2BUF;	
	
	timePeriod = current_value - previous_value;
	previous_value=current_value; 
	freq = (float)(8000000/timePeriod);
		
	IFS0bits.IC2IF= 0; //Clear bit IC1IF (IFS<2>)

}

void timer_init(void)
{
 	T2CON				=0;							//disable Timer2
 	TMR2				=0x0000;					//Timer2 reg
 	PR2					=0xffff;						//PR reg of Timer2
 	T2CONbits.TSIDL	= 0;							// configuring timer3
	T2CONbits.TCKPS	= 0b10;	                 			// 1:64 prescaler	
	T2CONbits.T32		= 1;							//Timer2 & Timer3 Configured as 32-bit Timer	
//	T3CON				= 0;							//desabling timer3
	TMR3				= 0X0000;					// TIMER3 REGISTER
	PR3					= _t3_time;					// time period
//	T3CONbits.TSIDL	= 0;							// configuring timer3
//	T3CONbits.TCKPS	= 0b10;	                 			// 1:641 prescaler						
	IFS0bits.T3IF			= 0;							// clear interrupt flag 
	IPC1bits.T3IP		= 7;							// set interrupt priority
	IEC0bits.T3IE		= 1;							// interrupt enable
	T2CONbits.TON		= ON;						// enable timer2
//	T3CONbits.TON		= ON;						// enable timer3
	printf("Timer ready\n");
}