89C51单片机中_nop_()报错

Question

#include<reg51.h>
#include<intrins.h>
#include<string.h>
#define uchar unsigned char
#define uint unsigned int

sbit CS=P1^0;
sbit CLK=P1^1;
sbit DIO=P1^2;

sbit RS=P2^0;
sbit RW=P2^1;
sbit E=P2^2;
#define LCD_PORT P0
uchar Disp_Buff1[]=" VOLTAGE: 0.00V";
uchar Disp_Buff2[16];

#define delay4us(){_nop_();_nop_(); _nop_();_nop();}
void delay_ms(uint x)
{
    uchar t;
    while(x--);
        for(t=0;t<120;t++);
}

bit Read_LCD_Busy_Flag()
{
    uchar result;
    LCD_PORT=0xFF;
    RS=0;RW=1;
    E=1; delay4us(); result=P0; E=0;
    return(result&0x80)?1:0;
}
void Write_LCD_Command(uchar cmd)
{
    while(Read_LCD_Busy_Flag());
    RS=0; RW=0;
    E=0; _nop()_; _nop()_; LCD_PORT=cmd;
    delay4us(); E=1; delay4us(); E=0;
}
void Write_LCD_Data(uchar dat)
{
    while(Read_LCD_Busy_Flag());
    RS=1; RW=0; 
    E=0; LCD_PORT=dat; delay4us();
    E=1; delay4us(); E=0;
}
void LCD_Show_String(uchar r,uchar c,char *s)
{
    uchar i=0;
    uchar code DDRAM[]={0x80,0xC0};
    Write_LCD_Command(DDRAM[r]|c);
    while(s[i]&&i<16)
        Write_LCD_Data(s[i++]);     
}
void LCD_Initialise()
{
    Write_LCD_Command(0x38); delay_ms(1);
    Write_LCD_Command(0x0C); delay_ms(1);
    Write_LCD_Command(0x06); delay_ms(1);
    Write_LCD_Command(0x01); delay_ms(1);
}

uchar Get_AD_Result()
{
    uchar i, dat1=0, dat2=0;
    CS=0;   CLK=0;

    DIO=1;          _nop()_;_nop()_;
    CLK=1;          _nop()_;_nop()_;

    CLK=0;  DIO=1;  _nop()_;_nop()_;
    CLK=1;          _nop()_;_nop()_;

    CLK=0;  DIO=0;  _nop()_;_nop()_;
    CLK=1;          _nop()_;_nop()_;

    CLK=0;  DIO=1;  _nop()_;_nop()_;

    for(i=0;i<8;i++)
    {
        CLK=1;      _nop()_;_nop()_;
        CLK=0;      _nop()_;_nop()_;
        dat1=(dat1<<1)|DIO;
    }   

    for(i=0;i<8;I++)
    {
        dat2=dat2|((uchar)DIO<<i);
        CLK=1;      _nop()_;_nop()_;
        CLK=0;      _nop()_;_nop()_;
    }
    CS=1;
    return(dat1==dat2)?dat1:0x00;
}

void main()
{
    uchar i,AD;uint d;
    LCD_Initialise();
    while(1)
    {
        AD=Get_AD_Result();
        d= A/D *500.0*2/511.0;
        Disp_Buff1[11]d/100 +'0';
        Disp_Buff1[13]=d/10%10  +'0';
        Disp_Buff1[14]=d%10 +'0';
        i=(uint)AD*16/255;
        memset(Disp_Buff2,'\xFF',i);
        memset(Disp_Buff2 +i,'\xDB',16-i);
        LCD_show_String(1,0,Disp_Buff2);
    }                      
}

请问各位大佬为什么我这个_nop_()会报错

Answer 1

你一会儿 _nop()_ 一会儿 _nop()
应该是 _nop_()