Problem With SD24 ADC Sampling rate

Hello,

I am facing some problem with SD24 ADC configuration. I was expected intrrupt at 200uS but it is going in ISR at 220uS. Here is my code

#include <msp430.h>
int main(void)
{
	WDTCTL = WDTPW | WDTHOLD;	// Stop watchdog timer
        P1DIR |= BIT0;
	/***** Unified Clock system ****/
	UCS_config();
        SD24_B_config();
         __delay_cycles(0x3600);                 // Delay for 1.5V REF startup


        SD24BCTL1 |= SD24GRP0SC;                // Set bit to start conversion

        __bis_SR_register( GIE);       // Enter interrupt

}
void UCS_config(void)
{
		PMMCTL0_H = 0xA5;
		PMMCTL0_L = 0x03;
		UCSCTL0 = UCSCTL0 | 0x1F00;
		UCSCTL1 = UCSCTL1 & 0x0000;
		UCSCTL1 = UCSCTL1 | 0x0040;
		UCSCTL2 = UCSCTL2 & 0x0000 ; // FLL Divider
		UCSCTL2 = UCSCTL2 | 0x304F ; // for 20 MHz MCLK and 2.6 MHz SMCLK
		UCSCTL3 = 0x0000;

		UCSCTL4 = UCSCTL4 & 0X0000;
		UCSCTL4 = UCSCTL4 | 0X0043;
}

void SD24_B_config(void)
{
	SD24BCTL0 = SD24REFS | SD24SSEL_1;      // Select internal REF // Select SMCLK as SD24_B clock source

	SD24BOSR0 = 0X0208;		//C7 for 5K samplin; OSR = 520
	SD24BOSR1 = 0X0208;		//C7 for 5K samplin; OSR = 520
	SD24BOSR2 = 0X0208;		//C7 for 5K samplin; OSR = 520
	SD24BOSR3 = 0X0208;		//C7 for 5K samplin; OSR = 520
	SD24BOSR4 = 0X0208;		//C7 for 5K samplin; OSR = 520
	SD24BOSR5 = 0X0208;		//C7 for 5K samplin; OSR = 520
	SD24BOSR6 = 0X0208;		//C7 for 5K samplin; OSR = 520


	SD24BCCTL0 = SD24ALGN | SD24SCS_4;      // Left-aligned, group 0
	SD24BCCTL1 = SD24ALGN | SD24SCS_4;      // Left-aligned, group 0
	SD24BCCTL2 = SD24ALGN | SD24SCS_4;      // Left-aligned, group 0
	SD24BCCTL3 = SD24ALGN | SD24SCS_4;      // Left-aligned, group 0
	SD24BCCTL4 = SD24ALGN | SD24SCS_4;      // Left-aligned, group 0
	SD24BCCTL5 = SD24ALGN | SD24SCS_4;      // Left-aligned, group 0
	SD24BCCTL6 = SD24ALGN | SD24SCS_4;      // Left-aligned, group 0

        SD24BIE = SD24IE5;
}
__interrupt void SD24BISR(void)
{

// Every 200 uSeconds
	 P1OUT ^= 0x0001;

	if(SD24BIV == SD24BIV_SD24IFG5)
	{
	//	P1OUT = 0x0001;

		Ch0results = SD24BMEMH0 - Ch0_Offset; // Save CH0 higher results (clears IFG)
		Ch4results = SD24BMEMH4 - Ch4_Offset; // Save CH4 higher results (clears IFG)

		Ch1results = SD24BMEMH1 - Ch1_Offset; // Save CH1 higher results (clears IFG)
		Ch5results = SD24BMEMH5 - Ch5_Offset; // Save CH5 higher results (clears IFG)

		Ch2results = SD24BMEMH2 - Ch2_Offset; // Save CH2 higher results (clears IFG)
		Ch6results = SD24BMEMH6 - Ch6_Offset; // Save CH6 higher results (clears IFG)

		Ch3results = SD24BMEMH3 - Ch3_Offset; // Save CH3 higher results (clears IFG)

		

	}
}

I have given output P1.0 to Digital Oscilloscope but it is showing toggling of bit at every 440uS. Which means I am going in my ISR at 220uS. Please let me know where I am making mistake.

Thanks in Advance

Regards

Abhishek