74LS164在单片机中的运用

在单片机体系中，假如并行口的IO资源不行，那么咱们能够运用74LS164来扩展并行IO口，节省单片机IO资源。74LS164是一个串行输入并行输出的移位寄存器，并带有铲除端。
74LS164的引脚能够检查数据手册。
proteus仿真图和代码附上。

#include

#define HIGH 1
#define LOW 0
#define SEG_PORT P0

sbit DATA = P0^4;
sbit CLK = P0^5;

unsigned char Timer0IRQEvent = 0;
unsigned char Time1SecEvent = 0;
unsigned int TimeCount = 0;
unsigned char SegCurPosition = 0;
code unsigned char SegCode[10] = {~0x3F,~0x06,~0x5B,~0x4F,~0x66,~0x6D,~0x7D,~0x07,~0x7F,~0x6F};
code unsigned char SegPosition[4] = {0xFE,0xFD,0xFB,0xF7};
unsigned char SegBuf[4] = {0};

void LS164_DATA(unsigned char x)
{
if(x)
{
DATA = 1;
}
else
{
DATA = 0;
}
}
void LS164_CLK(unsigned char x)
{
if(x)
{
CLK = 1;
}
else
{
CLK = 0;
}
}
/**********************************************************
*函数称号：LS164Send
*输 入：byte单个字节
*输 出：无
*功 能：74LS164发送单个字节
***********************************************************/
void LS164Send(unsigned char byte)
{
unsigned char j;
for(j=0;j<=7;j++)
{
if(byte&(1<<(7-j)))
{
LS164_DATA(HIGH);
}
else
{
LS164_DATA(LOW);
}
LS164_CLK(LOW);
LS164_CLK(HIGH);
}
}
/**********************************************************
*函数称号：SegRefreshDisplayBuf
*输 入：无
*输 出：无
*功 能：数码管改写显现缓存
***********************************************************/
void SegRefreshDisplayBuf(void)
{
SegBuf[0] = TimeCount%10;
SegBuf[1] = TimeCount/10%10;
SegBuf[2] = TimeCount/100%10;
SegBuf[3] = TimeCount/1000%10;
}