單片機+74HC595四位數碼管的驅動程序不太理解

ID:950830 · 發表于 2021-7-18 22:13

這是數碼管的例程
LED[0]=1;
LED[1]=2;
LED[2]=3;
LED[3]=4;
主程序的這四句不太理解，也沒有注釋希望有大佬能解釋一下

#include <AT89X51.H>
unsigned char code fseg[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};
unsigned char code segbit[]={0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01};
unsigned char disbuf[4]={0,0,0,0};
//-----------------------------------------------------------------------------
// 函數原形定義
#define uchar unsigned char
void main (void); // 主函數
void LED4_Display (void); // LED顯示
void LED_OUT(uchar X); // LED單字節串行移位函數
unsigned char code LED_0F[]; // LED字模表
sbit DIO = P1^0; //串行數據輸入
sbit RCLK = P1^1; //時鐘脈沖信號——上升沿有效
sbit SCLK = P1^2; //打入信號————上升沿有效
//-----------------------------------------------------------------------------
// 全局變量
uchar LED[8]; //用于LED的8位顯示緩存
//*****************************************************************************
// 主程序
//
void main (void)
{
LED[0]=1;
LED[1]=2;
LED[2]=3;
LED[3]=4;
while(1)
{
LED4_Display ();
}
}
void LED4_Display (void)
{
unsigned char code *led_table; // 查表指針
uchar i;
//顯示第1位
led_table = LED_0F + LED[0];
i = *led_table;
LED_OUT(i);
LED_OUT(0x01);
RCLK = 0;
RCLK = 1;
//顯示第2位
led_table = LED_0F + LED[1];
i = *led_table;
LED_OUT(i);
LED_OUT(0x02);
RCLK = 0;
RCLK = 1;
//顯示第3位
led_table = LED_0F + LED[2];
i = *led_table;
LED_OUT(i);
LED_OUT(0x04);
RCLK = 0;
RCLK = 1;
//顯示第4位
led_table = LED_0F + LED[3];
i = *led_table;
LED_OUT(i);
LED_OUT(0x08);
RCLK = 0;
RCLK = 1;
}
void LED_OUT(uchar X)
{
uchar i;
for(i=8;i>=1;i--)
{
if (X&0x80) DIO=1; else DIO=0;
X<<=1;
SCLK = 0;
SCLK = 1;
}
}
unsigned char code LED_0F[] =
{// 0 1 2 3 4 5 6 7 8 9 A b C d E F -
0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90,0x8C,0xBF,0xC6,0xA1,0x86,0xFF,0xbf
};