//***************************************************************************************

// Clock 3

// Use 32.768 KHz crystal for MCLK

//

// MSP430G2211

// Jed Margolin  2/27/2016.

//  Built with Code Composer Studio v6

//***************************************************************************************

// main.c

#include <msp430.h>

//#include <msp430G2211.h>

#define TIME 6

void wait(unsigned int);

void wait2(void);

//================================================

int main(void)

{

            volatile unsigned int k = 0;

            WDTCTL = WDTPW + WDTHOLD;           // Stop watchdog timer

            wait(200);                                           // give the crystal time to stabilize

            P1SEL  |= BIT0;                     // ACLK

//          P1SEL2 &= ~(BIT0);             // not used by msp430g2211

            P1DIR  |= BIT0;

            P1SEL  &= ~BIT1;                 // In

//          P1SEL2 |= BIT1;                    // not used by msp430g2211

            P1REN |= BIT1;                      // pullup/pulldown enabled

            P1OUT |= BIT1;                     //

            P1DIR &= ~(BIT1);               //

            P1SEL  &= ~BIT2;                 // Out

//          P1SEL2 |= BIT2;                    // not used by msp430g2211

            P1DIR |= BIT2;                       //

            P1SEL  &= ~(BIT3);              // Out - for testing

//          P1SEL2 &= ~(BIT3);             // not used by msp430g2211

            P1DIR |= BIT3;                       //

            P1SEL  |= BIT4;                     // Out for SMCLK so we know it's working

//          P1SEL2 &= ~(BIT4);             // not used by msp430g2211

            P1DIR |= BIT4;                       //

            P1SEL  &= ~(BIT5);              // In

//          P1SEL2 &= ~(BIT5);             // not used by msp430g2211

            P1REN |= BIT5;                      // pullup/pulldown enabled

            P1OUT |= BIT5;                     // pullup

            P1DIR &= ~(BIT5);               //

            P1SEL &= ~(BIT6);               // Out

//          P1SEL2 &= ~(BIT6);             // not used by msp430g2211

            P1DIR |= BIT6;                       // pullup

            P1DIR &= ~(BIT7);               // In - 60Hz phase

            P1OUT |= BIT7;                     // pullup

            P1SEL  &= ~(BIT7);              //

//          P1SEL2 &= ~(BIT7);             // not used by msp430g2211

            P1REN |= BIT7;                      // pullup/pulldown enabled

// Enable the crystal

// BCSCTL1 comes out of reset with:

//                      XT2OFF = 1 (MSP430G2553 and MSP430G2211 don't have XT2)

//                      XTS = 0 (LFXT1 = Low Frequency mode)

//                      DIVAx = 0 (ACLK Divider = 1)

//                      RSELx = 7 (Range Select - should be for DCO only)

            BCSCTL3 |= LFXT1S_0 + XCAP_3;

            // LFXT1S = 0 (32768 crystal on LFXT1

            // XCAP = 3 (12.5pF)

            while(IFG1 & OFIFG)            // OFIFG is Bit1 in IFG1 (Interrupt Flag Register)

                                                            //    and means oscillator fault

            {

                        IFG1 &= ~OFIFG;      // keep resetting it until it doesn't need to be reset

                        wait2();

            }

// We are going to leave SCG1 and SCG0 off

//          _bis_SR_register(SCG1 + SCG0);     // Set bits SCG1  and SCG0

//  SCG1 (System Clock Generator 1) When set turns off the SMCLK

//  SCG0 (System Clock Generator 0) When set turns off the DCO dc generator if DCOCLK is not used for MCLK or SMCLK

//  We will leave DCO dc generator on just in case

            BCSCTL2 = 0xC8;

// SELMx(7,6) = (1,1)  Select MCLK = LFXT1CLK or VLOCLK

// DIVMx(5,4) = (0,0)  MCLK Divider = /1

// SELS(3)    = (1)          SMCLK = LFXT1CLK or VLOCLK

// DIVSx(2,1) = (0,0)  SMCLK Divider = /1

// DCOR(0)    = (0)    not used

// end of setup for crystal

//-----------------------

            while (1)                                 // main loop

            {

                        P1OUT |= BIT6;

                        wait(TIME);

                        P1OUT &= ~(BIT6);

                        wait(TIME);

            }  // end main loop

}  // end main

//==================================

void wait(unsigned int time)

{

    volatile unsigned int i,j;

    for(i=time; i>0; i--)

    {

            for(j=249; j>0; j--);

            {

            }

    }

 return;

} // end wait

//==========================================================

void wait2()

{

volatile unsigned int i;

            for(i=0; i<48; i++){}

            return;

}  // end wait2

//========================================================