TIDM-3PHMTR-TAMP-ESD: MCLK frequency not as expected MSP430f6779

Hi,

We are using TIDM-3PHMTR-TAMP-ESD reference design hardware for smart meter development which uses MSP430f6779 controller.

We are using firmware code generated by ENERGY MEASUREMENT DESIGN CENTER tool.

The code is working fine on the development board, but when we tried adding our code in the same firmware, we found that code is taking abnormally high time even for simple comparison statement(1 us approx for two comparisons)

When we dig deeper to find the issue we found that MCLK is clocking the CPU at 2Mhz( We checked this by toggling the pin in while loop with all other code including interrupts bypassed) although it appears from the settings in the code MCLK is configured to run at 25MHz.

Second thing we tried by using following simple code to set MCLK

main()

{

    WDTCTL = WDTPW + WDTHOLD;
    P1DIR |= BIT4;
    UCSCTL0 |= 0x0200;
    UCSCTL1 = 0x0060;
    UCSCTL2 = 0x11FF;

    while(1)
    {
        P1OUT ^= BIT4; // Toggle P1.4
         __delay_cycles(1);
    }

}

We tried adjusting values in UCSCTL registers with no luck.

Thanks in advance for guiding us

Shekhar