【C51自学笔记】实时时钟芯片DS1302

第第页【C51自学笔记】实时时钟芯片DS1302简介：

芯片内部具有可编程日历时钟和31个字节的静态RAM，日历时钟可自动进行闰年补偿，计时准确，接口简单，使用方便，工作电压范围宽，功耗低，芯片自身还具有对备份电池进行涓流充电功能，可以有效地延长备份电池的使用寿命。

连接图：8051单片机与DS1302的一种接口电路#defineucharunsignedchar#defineuintunsignedint//时钟sbitsck=P1^0;sbitio=P1^1;sbitrst=P3^6;//数码管防误操作sbitsmgen=P2^3;unsignedcharcodesmg_du[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71,0x00,0x10};unsignedcharcodesmg_we[]={0x08,0x18,0x28,0x38,0x48,0x58,0x68,0x78};uchartime_data[7]={10,6,4,17,11,58,30};//年周月日时分秒ucharwrite_add[7]={0x8c,0x8a,0x88,0x86,0x84,0x82,0x80};ucharread_add[7]={0x8d,0x8b,0x89,0x87,0x85,0x83,0x81};uchardisp[8];//单字节写voidwrite_ds1302_byte(uchardat);//add+datavoidwrite_ds1302(ucharadd,uchardat);//单字节读ucharread_ds1302(ucharadd);//设置voidset_rtc(void);//读时间voidread_rtc(void);//数据处理与时间显示voidtime_pros(void);voiddisplay(void);voiddelay_50us(uintt){ucharj;for(;t>0;t--)for(j=19;j>0;j--);}voidwrite_ds1302_byte(uchardat){//rst在调用之前已经拉高uchari;for(i=0;i>1;sck=1;}}voidwrite_ds1302(ucharadd,uchardat){//initrst=0;_nop_();sck=0;_nop_();//writerst=1;_nop_();write_ds1302_byte(add);write_ds1302_byte(dat);rst=0;_nop_();io=1;sck=1;}ucharread_ds1302(ucharadd){uchari,value;rst=0;_nop_();sck=0;_nop_();rst=1;_nop_();write_ds1302_byte(add);for(i=0;i>1;sck=0;if(io)value=value|0x80;//10000000sck=1;}rst=0;_nop_();sck=0;_nop_();sck=1;io=1;returnvalue;}voidset_rtc(void){//对时BCD码uchari,j;//处理bcd码for(i=0;i<7;i++){j=time_data[i]/10;time_data[i]=time_data[i]%10;time_data[i]=time_data[i]+j*16;}write_ds1302(0x8e,0x00);//去除写保护for(i=0;i<7;i++){write_ds1302(write_add[i],time_data[i]);}write_ds1302(0x8e,0x80);//加写保护}voidread_rtc(void){uchari;for(i=0;i<7;i++){time_data[i]=read_ds1302(read_add[i]);}}voidtime_pros(void){disp[0]=time_data[6]%16;disp[1]=time_data[6]/16;disp[2]=16;disp[3]=time_data[5]%16;disp[4]=time_data[5]/16;disp[5]=16;disp[6]=time_data[4]%16;disp[7]=time_data[4]/16;}voiddisplay(void){uchari;for(i=0;i<8;i++){P1=smg_du[disp[i]];P2=smg_we[i];delay_50us(20);}}voidma