/**********************************************
程序功能：在六位數碼管上顯示一個繞動的光圈，光
          圈的速度自由變化（快-->慢-->快）
-----------------------------------------------
測試說明：觀察數碼管顯示
***********************************************/
#include  <msp430x14x.h>
#include  "BoardConfig.h"

#define NBIT(x)     ~(1 << x)

//繞動光圈對應的字符
uchar scandata[16] = {0x01,0x01,0x01,0x01,0x01,0x01,0x20,0x10,
                      0x08,0x08,0x08,0x08,0x08,0x08,0x04,0x02};
//顯示字符的控制變量
uchar step = 0;
//繞動圈數的變量
uint circle = 0;

/********************主函數********************/
void main(void)
{
    WDTCTL = WDTPW + WDTHOLD;       //關閉看門狗    
    BoardConfig(0x88);
  
    P4DIR = 0xff;                 //設置P4，P5的IO方向為輸出
    P5DIR = 0xff;                 
  
    P4OUT = 0x00;                 //設置P4，P5的輸出初值
    P5OUT = 0xff;
    
    CCR0 = 164;
    TACCTL0 |= CCIE;              //使能比較中斷
    TACTL |= TASSEL_1 + MC_1;     //ACLK, up mode
  
    _BIS_SR(LPM3_bits + GIE);     //CPU進入LPM3低功耗模式，同時打開全局中斷
}

/*******************************************
函數名稱：TimerA_ISR
功    能：定時器A中斷服務函數，在這里輸出數碼管的
          段選和位選信號
參    數：無
返回值  ：無
********************************************/
#pragma vector=TIMERA0_VECTOR
__interrupt void TimerA_ISR(void)
{ 
    step++;
    if(step == 16)  
    {
        step = 0;
        circle++;
        if(circle == 10)        //如果已經繞動了10圈
        {
            circle = CCR0;
            CCR0 += circle;     //速度降為原來的一半
            if(CCR0 > 32700)    //如果速度到達底線，則從頭開始
                CCR0 = 164;     
            circle = 0;
        }
    }
    switch(step)
    {
    case 0:
            P5OUT = NBIT(5);
            P4OUT = scandata[step];
            break;
    case 1: 
            P5OUT = NBIT(4);
            P4OUT = scandata[step];
            break;
    case 2:
            P5OUT = NBIT(3);
            P4OUT = scandata[step];
            break;
    case 3: 
            P5OUT = NBIT(2);
            P4OUT = scandata[step];
            break;
    case 4:
            P5OUT = NBIT(1);
            P4OUT = scandata[step];
            break;
    case 5:
            P5OUT = NBIT(0);
            P4OUT = scandata[step];
            break;
    case 6:
            P5OUT = NBIT(0);
            P4OUT = scandata[step];
            break;
    case 7:
            P5OUT = NBIT(0);
            P4OUT = scandata[step];
            break;
    case 8:
            P5OUT = NBIT(0);
            P4OUT = scandata[step];
            break;
    case 9:
            P5OUT = NBIT(1);
            P4OUT = scandata[step];
            break;
    case 10:
            P5OUT = NBIT(2);
            P4OUT = scandata[step];
            break;
    case 11:
            P5OUT = NBIT(3);
            P4OUT = scandata[step];
            break;
    case 12:
            P5OUT = NBIT(4);
            P4OUT = scandata[step];
            break;
    case 13:
            P5OUT = NBIT(5);
            P4OUT = scandata[step];
            break;
    case 14:
            P5OUT = NBIT(5);
            P4OUT = scandata[step];
            break;
    case 15:
            P5OUT = NBIT(5);
            P4OUT = scandata[step];
            break;
    }
}