定时器c 语言程序.doc

定时器c 语言程序#include c8051f020.h #include /*函数声明*/void write7279(unsigned char, unsigned char);/写入到HD7279void Send7279Byte(unsigned char ch); /发送一个命令字void Delay1us(unsigned char us) ; /延时1void Delay1ms(unsigned char T) ; /延时1msvoid Timer0_Init (void);void SYSCLK_Init (void); /* 变量及I/O口定义 * unsigned char data shi _at_ 0x30; /时unsigned char data fen _at_ 0x31; /分unsigned char data miao _at_ 0x32; /秒unsigned char data zdjs _at_ 0x33; /中断计数unsigned char bdata BZW _at_ 0x20; sbit BZW0=BZW0; sbit CLK = P16; / HD7279sbit DAT = P17; / HD7279#define NOSELECT7279 P5 |= 0x80/SPICS4(P57)=1#define SELECT7279 P5 &= (0x80) /SPICS4(P57)=0 /*延时N * 1*/ void Delay1us(unsigned char us) /延时1while (us) _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); -us; /*发送一个命令字*/void Send7279Byte(unsigned char ch) /发送一个命令字char i; SELECT7279;/置CS低电平 Delay1us(100);/延时50for (i=0;i0x8;i+)if (ch&0x80)/输出7位到HD7279A的DATA端 DAT=1;elseDAT=0;CLK=1;/置CLK高电平 ch=ch1;/待发数据左移 Delay1us(20);/延时8CLK=0;/置CLK低电平 Delay1us(20);/延时50DAT=0;/发送完毕，DATA端置低，返回 /* 显示时钟 */void displaytime()/显示时钟Send7279Byte(0x85) ;Send7279Byte(shi/10) ; /显示 时的 十位Send7279Byte(0x84) ;Send7279Byte(shi%10) ;/显示 时的 个位Send7279Byte(0x83) ;Send7279Byte(fen/10) ; /显示 分的 十位Send7279Byte(0x82) ; Send7279Byte(fen%10) ; /显示 分的 个位Send7279Byte(0x81) ;Send7279Byte(miao/10); /显示 秒的 十位Send7279Byte(0x80);Send7279Byte(miao%10); /显示 秒的 个位 /*单片机时钟初始化*/void SYSCLK_Init (void) int i; / delay counter OSCXCN = 0x65; / start external oscillator with / 18.432MHz crystal for (i=0; i =50) BZW0=1; zdjs=0;miao = miao +1; /是否到 1s 了？if(miao=60) miao =0; fen+=1;if(fen=60) fen=0;shi+=1; if( shi=24) shi=0; fen=0; miao=0; /*主程序*/void main (void) WDTCN = 0xde;WDTCN = 0xad; /关看门狗 SYSCLK_Init (); /初始化时钟Timer0_Init();/初始化定时器PORT_Init (); /初始化IO口 CPT1CN |= 0x80;/使能比较器1 REF0CN = 0x03; /使能片内参考电压 EA=1;/开中断 BZW0=0; shi= 22;fen = miao = zdjs =0