Question

keil中已经定义了为什么编译还说未定义？

#include "1602.h"
#include "delay.h"
sbit RS = P2^4; //定义端口
sbit RW = P2^5;
sbit EN = P2^6;

#define RS_CLR RS=0
#define RS_SET RS=1

#define RW_CLR RW=0
#define RW_SET RW=1

#define EN_CLR EN=0
#define EN_SET EN=1
#define DataPort P0

/*---------------判忙函数----------------*/
bit LCD_Check_Busy(void)
{
DataPort = 0xFF;
RS_CLR;
RW_SET;
EN_CLR;
_nop_();
EN_SET;
return (bit)(DataPort & 0x80);
}

编译显示：
LCD1602.C(3): error C202: 'P2': undefined identifier
LCD1602.C(4): error C202: 'P2': undefined identifier
LCD1602.C(5): error C202: 'P2': undefined identifier
LCD1602.c(7): warning C317: attempt to redefine macro 'RS_CLR'
LCD1602.C(20): error C202: 'P0': undefined identifier
LCD1602.C(21): error C202: 'RS': undefined identifier
LCD1602.C(22): error C202: 'RW': undefined identifier
LCD1602.C(23): error C202: 'EN': undefined identifier

Answer 1

给你个C51的汇编参考 star: mov dptr,#numtab ;指定查表启始地址 mov a,#3 ;显示3，你可以改变该数显示 MOVC A,@A+DPTR mov p0,a clr p2.0 ;开个位显示 ljmp $ ;段数码管各划的数字排列表 numtab: db 0c0h,0f9h,0a4h,0b0h,99h,92h,82h,0f8h,80h