在这个程序中的作用是干啥滴

只看该作者 · 2017-1-9 18:51

/***************************************************
程序功能：动态显示文字“welcome”
----------------------------------------------------
拨码开关设置：将LCD位拨至ON，其余拨至OFF
测试说明：观察液晶显示
****************************************************/

uchar *s1 = "welcome!";

void main( void )
{

/*下面六行程序关闭所有的IO口*/
P1DIR = 0XFF; P1OUT = 0XFF;
P2DIR = 0XFF; P2OUT = 0XFF;
P3DIR = 0XFF; P3OUT = 0XFF;
P4DIR = 0XFF; P4OUT = 0XFF;
P5DIR = 0XFF; P5OUT = 0XFF;
P6DIR = 0XFF; P6OUT = 0XFF;

uchar i;
WDTCTL = WDT_ADLY_250;             //间隔定时器，定时16ms
P6DIR |= BIT2; P6OUT |= BIT2;       //关闭电平转换

LcdReset();
DispStr(4,0,s1);
LocateXY(0,9);                   //确定写入字符的显示位置
LcdWriteCommand(0x07, 1);          //整体显示左移
for(i = 12; i > 0; i--)
{
      LcdWriteData(0x20);
      //延时250ms
      IFG1 &= ~WDTIFG;
      while(!(IFG1 & WDTIFG));
      IFG1 &= ~WDTIFG;
}
while(1)
{
      LcdWriteCommand(0x05, 1);          //整体显示右移

      for(i = 24; i > 0; i--)
      {
         LcdWriteData(0x20);
         //延时250ms
         IFG1 &= ~WDTIFG;
         while(!(IFG1 & WDTIFG));
         IFG1 &= ~WDTIFG;
      }

      LcdWriteCommand(0x07, 1);          //整体显示左移

      for(i = 24; i > 0; i--)
      {
         LcdWriteData(0x20);
         //延时250ms
         IFG1 &= ~WDTIFG;
         while(!(IFG1 & WDTIFG));
         IFG1 &= ~WDTIFG;
      }
}
}
为什么要用  WDTCTL = WDT_ADLY_250;             //间隔定时器，定时16ms