阿里云网站建设考试题目南昌seo外包公司

1.引用头文件的两种方式

#include <reg52.h>
#include "reg52.h"

区别:优先搜索的位置不同!

在keil软件中

#include <reg52.h> 优先搜索软件安装的INC文件夹

#include "reg52.h" 优先搜索当前工程文件夹下的头文件,如果没有,则在软件安装的INC文件夹下搜索头文件

2.如何方便地打开头文件

光标定位到头文件处,右击打开

3.reg52.h内容

#ifndef __REG52_H__
#define __REG52_H__/*  BYTE Registers 8位寄存器 */ 
sfr P0    = 0x80;
sfr P1    = 0x90;
sfr P2    = 0xA0;
sfr P3    = 0xB0;
sfr PSW   = 0xD0;
sfr ACC   = 0xE0;
sfr B     = 0xF0;
sfr SP    = 0x81;
sfr DPL   = 0x82;
sfr DPH   = 0x83;
sfr PCON  = 0x87;
sfr TCON  = 0x88;
sfr TMOD  = 0x89;
sfr TL0   = 0x8A;
sfr TL1   = 0x8B;
sfr TH0   = 0x8C;
sfr TH1   = 0x8D;
sfr IE    = 0xA8;
sfr IP    = 0xB8;
sfr SCON  = 0x98;
sfr SBUF  = 0x99;/*  8052 Extensions 8052拓展部分 */
sfr T2CON  = 0xC8;
sfr RCAP2L = 0xCA;
sfr RCAP2H = 0xCB;
sfr TL2    = 0xCC;
sfr TH2    = 0xCD;/*  BIT Registers 位寄存器(合起来为标志寄存器 Flags Register) */
/*  PSW  */
sbit CY    = PSW^7;
sbit AC    = PSW^6;
sbit F0    = PSW^5;
sbit RS1   = PSW^4;
sbit RS0   = PSW^3;
sbit OV    = PSW^2;
sbit P     = PSW^0; //8052 only/*  TCON 定时器控制 */
sbit TF1   = TCON^7;
sbit TR1   = TCON^6;
sbit TF0   = TCON^5;
sbit TR0   = TCON^4;
sbit IE1   = TCON^3;
sbit IT1   = TCON^2;
sbit IE0   = TCON^1;
sbit IT0   = TCON^0;/*  IE 中断允许 */
sbit EA    = IE^7;
sbit ET2   = IE^5; //8052 only
sbit ES    = IE^4;
sbit ET1   = IE^3;
sbit EX1   = IE^2;
sbit ET0   = IE^1;
sbit EX0   = IE^0;/*  IP 中断优先级 */
sbit PT2   = IP^5;
sbit PS    = IP^4;
sbit PT1   = IP^3;
sbit PX1   = IP^2;
sbit PT0   = IP^1;
sbit PX0   = IP^0;/*  P3 端口3 */
sbit RD    = P3^7;
sbit WR    = P3^6;
sbit T1    = P3^5;
sbit T0    = P3^4;
sbit INT1  = P3^3;
sbit INT0  = P3^2;
sbit TXD   = P3^1;
sbit RXD   = P3^0;/*  SCON 串行口控制 */
sbit SM0   = SCON^7;
sbit SM1   = SCON^6;
sbit SM2   = SCON^5;
sbit REN   = SCON^4;
sbit TB8   = SCON^3;
sbit RB8   = SCON^2;
sbit TI    = SCON^1;
sbit RI    = SCON^0;/*  P1 端口1 */
sbit T2EX  = P1^1; // 8052 only
sbit T2    = P1^0; // 8052 only/*  T2CON  */
sbit TF2    = T2CON^7;
sbit EXF2   = T2CON^6;
sbit RCLK   = T2CON^5;
sbit TCLK   = T2CON^4;
sbit EXEN2  = T2CON^3;
sbit TR2    = T2CON^2;
sbit C_T2   = T2CON^1;
sbit CP_RL2 = T2CON^0;#endif

备注:,sfr(定义特殊功能寄存器) sbit(定义特殊功能寄存器的位变量)

定义格式: sfr 特殊功寄存器名 = 地址;

                sbit 寄存器名 = 寄存器^数字;

如:

sfr P0    = 0x80;
sbit CY    = PSW^7;

定义特殊功能寄存器P0地址值为0x80(P0的值为0x80处地址的值)

定义位寄存器CY为PSW的第7位