P44-P45-P46-应用例子.zip_8RS_NBH_P44-P45-P46-应用例子_STC12单片机_stc12的p44

/*------------------------------------------------------------------*/ /* --- STC MCU International Limited -------------------------------*/ /* --- STC 1T Series MCU Programme Demo ----------------------------*/ /* --- Fax: 86-755-82944243 ----------------------------------------*/ /* --- Tel: 86-755-82948412 ----------------------------------------*/ /* --- Web: www.STCMCU.com -----------------------------------------*/ /* If you want to use the program or the program referenced in the */ /* article, please specify in which data and procedures from STC */ /*------------------------------------------------------------------*/ /* 本程序经过测试完全正常, 不提供电话技术支持, 如不能理解, 请自行补充相关基础. */ /************* 本程序功能说明 ************** 测试P4.4 P4.5 P4.6做IO输出方波。 ****************************************************/ #include <reg51.h> sfr P4 = 0xC0; sfr P4SW = 0xBB; sfr P4M1 = 0xB3; //P4M1.n,P4M0.n =00--->Standard, 01--->push-pull sfr P4M0 = 0xB4; // =10--->pure input, 11--->open drain sbit P44 = P4^4; sbit P45 = P4^5; sbit P46 = P4^6; sbit P47 = P4^7; void main(void) { unsigned int i; P4SW |= (1<<4); //P4.4允许设置成IO P4SW |= (1<<5); //P4.5允许设置成IO P4SW |= (1<<6); //P4.6允许设置成IO P4M1 &= ~(1<<4); //P4.4设置成准双向IO P4M0 &= ~(1<<4); P4M1 &= ~(1<<5); //P4.5设置成准双向IO P4M0 &= ~(1<<5); P4M1 &= ~(1<<6); //P4.6设置成准双向IO P4M0 &= ~(1<<6); // P4M1 &= ~(1<<7); //P4.7设置成PUSH-PULL 要在下在时指定RESET pin用做P4.7，并且使用外部晶体时钟 // P4M0 |= (1<<7); while(1) { for(i=0; i<1000; i++) ; //延时 P44 = ~P44; //取反输出方波 P45 = ~P45; P46 = ~P46; // P47 = ~P47; //要在下载时指定RESET pin用做P4.7，并且使用外部晶体时钟 } }