51 MCU C programming (fifteen 74HC595 control four-digit digital tube)

#include
#include

#define uchar unsigned char
#define uint unsigned int

uchar code DAT[10]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x02,0xf8,0x00,0x10};
sbit SDATA_595=P1^0;   //Serial data input
sbit SCLK_595=P1^1;    //Shift clock pulse
sbit RCK_595=P1^2;     //Output latch control pulse

sbit P20=P2^0;
sbit P21=P2^1;
sbit P22=P2^2;
sbit P23=P2^3;
sbit P24=P2^4;
sbit P25=P2^5;
sbit P26=P2^6;
sbit P27=P2^7;
sbit P30=P3^0;
sbit P31=P3^1;

uchar temp;

void delay(int ms) 
{
 int k;
 while(ms--)
 {
  for(k=0;k<250;k++)
  {
   _nop_();
   _nop_();
  
  }
 }
}

void WR_595(void)       //Send the displayed data to the internal shift register of 74HC595
{
 uchar j;
   for(j=0;j<8;j++)
   {
     temp=temp<<1;
     SDATA_595=CY;
     SCLK_595=1;
    _nop_();
  _nop_();
  SCLK_595=0;
   }
}

void OUT_595(void)      //Store the data in the shift register to the output register and display it
{
   RCK_595=0;
   _nop_();
   _nop_();
   RCK_595=1;   //Send the data to the output latch on the rising edge_nop_
   ();
   _nop_();
   _nop_();
   RCK_595=0;
}

void key_scan()
{
 if(P20==0)
 { while
  (P20==0) ; temp=DAT
  [1]; WR_595();
  OUT_595 ();
  }
 if
 ( P21==0)
 { while(P21==0); temp = DAT [ 2 ]; WR_595 (); OUT_595 (); } if ( WR_59 5 ( ) ; OUT_595(); } if(P25==0) { while(P25==0); temp=DAT[6]; WR_595(); OUT_595(); } if(P26==0) { while(P26==0); temp=DAT[7]; WR_595(); OUT_595(); } if(P27==0) { while(P27==0); temp=DAT[8]; WR_595(); OUT_595(); } if(P30==0) { while(P30==0); temp=DAT[9]; WR_595(); OUT_595(); } if(P31==0) { while(P31==0); temp=DAT[0]; WR_595(); OUT_595(); } } void main() { SCLK_595=0; RCK_595=1; while(1) { key_scan(); //uchar i; //for(i=0;i<10;i++) //{ //   temp=DAT[i];  //Get display data //  WR_595(); //  OUT_595(); //  delay(200); //} } }