MSP430 MCU key program

MSP 430 MCU key program

#include  
#include "key.h" 

void Init_Port(void) 
{ 
    //Set all pins of P1 port to input mode during initialization 
    P1DIR = 0;

  
    //Set all pins of P1 port as general I/O ports 
    P1SEL = 0; 
     
    //Set P1.4 P1.5 P1.6 P1.7 as output direction 
    P1DIR |= BIT4; 
    P1DIR |= BIT5; 
    P1DIR |= BIT6; 
    P1DIR |= BIT7; 

    //Output low level 
    P1OUT = 0x00; 

    //Clear the interrupt register 
    P1IE = 0; 
    P1IES = 0; 
    P1IFG = 0; 
    //Turn on the interrupt function of the pin 
    //The corresponding pin jumps from high to low level to set the corresponding flag 
    P1IE |= BIT0;     
    P1IES |= BIT0;     
    P1IE |= BIT1;     
    P1IES |= BIT1; 
    P1IE |= BIT2;     
    P1IES |= BIT2      ;
    P1IE |= BIT3;     
    P1IES |= BIT3; 
    _EINT();//Turn on interrupt 
    return; 
} 
void Delay(void) 
{ 
    int i; 
    for(i = 100;i > 0;i--); //delay a little time 
} 
int KeyProcess(void) 
{ 
    int nP10; 
    int nP11; 
    int nP12; 
    int nP13; 
    int nRes = 0; 
    //P1.4 outputs low level 
    P1OUT &= ~(BIT4); 
    nP10 = P1IN & BIT0; 
    if (nP10 == 0) nRes = 13; 
    nP11 = (P1IN & BIT1) >> 1; 
    if (nP11 == 0) nRes = 14; 
    nP12 = (P1IN & BIT2) >> 2; 
    if (nP12 == 0) nRes = 15; 
    nP13 = (P1IN & BIT3) >> 3; 
    if (nP13 == 0) nRes = 16; 
    //P1.5 outputs low level 
    P1OUT &= ~(BIT4); 
    nP10 = P1IN & BIT0; 
    if (nP10 == 0) nRes = 9; 
    nP11 = (P1IN & BIT1) >> 1; 
    if (nP11 == 0) nRes = 10; 
    nP12 = (P1IN & BIT2) >> 2; 
    if (nP12 == 0) nRes = 11; 
    nP13 = (P 1IN & BIT3) >> 3; 
    if (nP13 == 0) nRes = 12; 
    //P1.6 outputs low level 
    P1OUT &= ~(BIT4); 
    nP10 = P1IN & BIT0; 
    if (nP10 == 0) nRes = 5; 
    nP11 = (P1IN & BIT1) >> 1; 
    if (nP11 == 0) nRes = 6; 
    nP12 = (P1IN & BIT2) >> 2; 
    if (nP12 == 0) nRes = 7; 
    nP13 = (P1IN & BIT3) >> 3; 
    if (nP13 == 0) nRes = 8; 
    //P1. 7 Output low level
    P1OUT &= ~(BIT4); 
    nP10 = P1IN & BIT0; 
    if (nP10 == 0) nRes = 1; 
    nP11 = (P1IN & BIT1) >> 1; 
    if (nP11 == 0) nRes = 2; 
    nP12 = (P1IN & BIT2) >> 2; 
    if (nP12 == 0) nRes = 3; 
    nP13 = (P1IN & BIT3) >> 3; 
    if (nP13 == 0) nRes = 4; 

    P1OUT = 0x00;//Restore the previous value. 

    //Read the status of each pin 
    nP10 = P1IN & BIT0; 
    nP11 = (P1IN & BIT1) >> 1; 
    nP12 = (P1IN & BIT2) >> 2; 
    nP13 = (P1IN & BIT3) >> 3; 
    for(;;) 
    { 
        if(nP10 == 1 && nP11 == 1 && nP12 == 1 && nP13 == 1) 
        { 
            //Wait for the key to be released 
            break; 
        } 
    } 
    return nRes; 
} 
//Handle interrupt from port 1 
#if __VER__ < 200 
    interrupt [PORT1_VECTOR] void PORT_ISR(void) 
#else 
    #pragma vector=PORT1_VECTOR 
    __interrupt void PORT_ISR(void) 
#endif 
{ 
    Delay(); 
    KeyProcess(); 
    if(P1IFG & BIT0) 
    {         
        P1IFG &= ~(BIT0);// Clear interrupt flag 
    } 
    if(P1IFG & BIT1) 
    { 
        P1IFG &= ~(BIT1);// Clear interrupt flag 
    } 
    if(P1IFG & BIT2) 
    { 
        P1IFG &= ~(BIT2);// Clear interrupt flag 
    } 
    if(P1IFG & BIT3) 
    { 
        P1IFG &= ~(BIT3);// Clear interrupt flag 
    } 
} 
void Init_CLK(void) 
{ 
    unsigned int i; 
    BCSCTL1 = 0X00; // Clear the contents of the register 
                    // XT2 oscillator is turned on 
                    // LFTX1 works in low frequency mode  // The division
factor                     of ACLK is 1      do       {      IFG1 &= ~OFIFG; // Clear OSCFault flag      for (i = 0x20; i > 0; i--);                      }      while ((IFG1 & OFIFG) == OFIFG); // If OSCFault = 1         BCSCTL2 = 0X00; // Clear the contents of the register      BCSCTL2 += SELM1; // The clock source of MCLK is TX2CLK, and the division factor is 1      BCSCTL2 += SELS; //The clock source of SMCLK is TX2CLK, and the division factor is 1  } 
                     






                     

key.h

void Init_CLK(void);
int KeyProcess(void);
void Delay(void);
int KeySCAN(void);
void Init_Port(void);