74HC595驱动（2线串行通信）

 

/*****************************************************************************
FileName : hc595.c
Function : 74HC595驱动程序---驱动74HC595,3入8出 
Author   : mike
Email    : [email protected]	
Version  : V1.0
Date     : 2019-07-12
Note     : 
*****************************************************************************/
#define u8                          unsigned char  
#define BIT(n)                      (1 << n)

#define HC595_INIT()                //初始化为输出
  
#define HC595_SI_HIGH()             P2 |= BIT(3)//Serial data---串行数据输入  
#define HC595_SI_LOW()              P2 &= ~BIT(3)     
#define HC595_SCK_HIGH()            P2 |= BIT(6)//storage register clock---存储寄存器时钟  
#define HC595_SCK_LOW()             P2 &= ~BIT(6)  
#define HC595_RCK_HIGH()            P2 |= BIT(4)//shift register clock---移位寄存器时钟  
#define HC595_RCK_LOW()             P2 &= ~BIT(4)     
  
void hc595_send_data(u8 dat)//写数据---1片74HC595  
{  
    u8 i;  
      
    for(i = 0;i < 8;i ++)  
    {  
        if(dat & 0x80)  
        {  
            HC595_SI_LOW();    //低亮< 如果需要高亮HC595_SI_HIGH() >        
        }  
        else  
        {  
            HC595_SI_HIGH();              
        }  
        dat <<= 1;  
        HC595_SCK_LOW();    //从SCK产生一上升沿(移入数据)  
        //asm("nop");asm("nop");asm("nop");asm("nop"); //稍做延时  
        HC595_SCK_HIGH();  
    }  
       //送数据  
    HC595_RCK_LOW();  
    //asm("nop");asm("nop");asm("nop");asm("nop"); //稍做延时  
    HC595_RCK_HIGH();  
    as//asm("nop");asm("nop");asm("nop");asm("nop"); //稍做延时  
    HC595_RCK_LOW();  
}  
  
void hc595_send_data(u32 dat)//写数据---4片74HC595级联  
{  
    u8 i;  
      
    for(i = 0;i < 32;i ++)  
    {  
        if(dat & 0x80000000)  
        {  
            HC595_SI_LOW();    //低亮 <如果需要高亮HC595_SI_HIGH() >        
        }  
        else  
        {  
            HC595_SI_HIGH();              
        }  
        dat <<= 1;  
        HC595_SCK_LOW();//从SCK产生一上升沿(移入数据)  
        //asm("nop");asm("nop");asm("nop");asm("nop"); //稍做延时  
        HC595_SCK_HIGH();  
    }  
       //送数据  
    HC595_RCK_LOW();  
    //asm("nop");asm("nop");asm("nop");asm("nop"); //稍做延时  
    HC595_RCK_HIGH();  
    //asm("nop");asm("nop");asm("nop");asm("nop"); //稍做延时  
    HC595_RCK_LOW();  
}