void ConfigurePLL ( void )
{
    unsigned int MValue, NValue;

    if ( PLLSTAT & (1 << 25) )
    {
        PLLCON = 1;            /* Enable PLL, disconnected */
        PLLFEED = 0xaa;
        PLLFEED = 0x55;
    }

    PLLCON = 0;                /* Disable PLL, disconnected */
    PLLFEED = 0xaa;
    PLLFEED = 0x55;
    
    SCS |= 0x20;            /* Enable main OSC */
    while( !(SCS & 0x40) );    /* Wait until main OSC is usable */

    CLKSRCSEL = 0x1;        /* select main OSC, 12MHz, as the PLL clock source */

    PLLCFG = PLL_MValue | (PLL_NValue << 16);
    PLLFEED = 0xaa;
    PLLFEED = 0x55;
      
    PLLCON = 1;                /* Enable PLL, disconnected */
    PLLFEED = 0xaa;
    PLLFEED = 0x55;

    CCLKCFG = CCLKDivValue;    /* Set clock divider */
#if USE_USB
    USBCLKCFG = USBCLKDivValue;        /* usbclk = 288 MHz/6 = 48 MHz */
#endif

    while ( ((PLLSTAT & (1 << 26)) == 0) );    /* Check lock bit status */
    
    MValue = PLLSTAT & 0x00007FFF;
    NValue = (PLLSTAT & 0x00FF0000) >> 16;
    while ((MValue != PLL_MValue) && ( NValue != PLL_NValue) );

    PLLCON = 3;                /* enable and connect */
    PLLFEED = 0xaa;
    PLLFEED = 0x55;
    while ( ((PLLSTAT & (1 << 25)) == 0) );    /* Check connect bit status */
}

    while ((MValue != PLL_MValue) && ( NValue != PLL_NValue) );

    uint32_t readback;

    /* Check if PLL is connected, disconnect if yes */
    if( PLLSTAT & PLLSTAT_PLLC )
    {
        PLLCON        = PLLCON_PLLE; // PLL enabled and disconnected
        PLLFEED        = 0xaa;
        PLLFEED        = 0x55;
    }

    PLLCON        = 0;                // PLL disabled
    PLLFEED        = 0xaa;
    PLLFEED        = 0x55;

    SCS|=            SCS_OSCEN;        // Enable main OSC

    while(!(SCS & SCS_OSCSTAT));    // Wait until OSC is usable

    CLKSRCSEL = CLKSRC_MAIN_OSC;    // Select main OSC as the PLL clock source

    /* Select PLL multiplier and devider */
    PLLCFG        = ( mainPLL_MUL | mainPLL_DIV );
    PLLFEED        = 0xaa;
    PLLFEED        = 0x55;

    PLLCON        = PLLCON_PLLE;        // Enable PLL, disconnected
    PLLFEED        = 0xaa;
    PLLFEED        = 0x55;

    /* Set clock devider */
    CCLKCFG        = mainCPU_CLK_DIV;

    //USBCLKCFG    = USBCLK_DIV_VALUE;

    /* Waiting for the PLL achieve lock */
    while(!(PLLSTAT & PLLSTAT_PLOCK));

    readback     = PLLSTAT & 0x00FF7FFF;
    /* stall - invalid readback */
    while (readback != (mainPLL_MUL | mainPLL_DIV));

    /* Enable and connect */
    PLLCON         = (PLLCON_PLLE | PLLCON_PLLC);
    PLLFEED     = 0xaa;
    PLLFEED     = 0x55;
    /* Check connect bit status, wait for connect */
    while(!(PLLSTAT & PLLSTAT_PLLC));