DS1302的读写
DS1302是DALLAS公司的一個時鐘芯片,能設置秒、分鐘、小時、月、星期、年,且年可以設置到2100年。有時鐘/日歷寄存器還有31*8位的額外數據暫存寄存器(RAM),可以存儲對時間的修正參數或者初始化的標志(前提是DS1302要外接備用電源),如果主機掉電后重新上電時讀取RAM中的初始化標志為1的話就不對DS1302初始化了。
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說到備用電源,可以用3.3v的鋰電池或者電源掉電時間短的話(幾小時或一天)則可以使用大電容(0.1F以上)供電,只是貌似電容體積太大。
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DS1302是通過三根線控制讀寫數據的,RST/SCL/IO.
RST:復位線,所有數據的讀寫,都需要保持RST為1,為0時就會終止當前的數據操作。
SCL:時鐘線,提供數據操作的同步時鐘。
?????寫入數據時,寫入數據在SCL=0時可以改變而在SCL=1時要保持不變,即數據會在SCL的上升沿寫入到DS1302。數據傳輸是低位在前,高位在后。
?????讀取數據時,在SCL=1變為SCL=0之后就可以讀取數據(注:在寫完寄存器后的一個下降沿就可以讀取數據),即數據會在SCL的下降沿出現到IO數據線上。同樣數據也是低位在前高位在后。
IO:數據線,要發送的八位數據,要從最低位一次移到IO數據線上。
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時鐘/日歷寄存器:
秒?:?
???? 1000..R/W是寄存器地址和讀寫控制位,R/W為1為讀,為0為寫。后面是寄存器里的讀寫數據,均是以二進制的BCD碼存在的。BCD碼,0-9對應0000-1001,十位對應10sec,如59對應數據為,CH1011001。下面幾個寄存器數據格式亦是如此。CH=1,代表晶振停振,CH=0,代表晶振起振,時鐘要工作的話都需要起振的。
分?:?
小時?:?
?????? bit7控制是1為12小時制,為0是24小時制,bit5為1則選擇12小時下的PM,為0則是選擇24小時的20-23小時段。
日?:?
月?:?
星期?:?
年?:?
CONTROL :?
????????? WP寫保護位,寫入時要置WP=0
還有涓流充電器寄存器,控制鋰電池的充電電流。
???????? DS1302的突發模式是連續讀寫寄存器,時鐘/日歷的7個寄存器是必須一下讀完的,而其他的寄存器沒必要一下讀完。
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?????????讀寫時序,貼張圖,詳見DS1302的資料手冊。
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突發模式的讀寫沒寫,連續讀寫和普通讀寫就是控制指令的bit5-bit1全為1,bit6控制連續讀寫時鐘/日歷或RAM。
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控制器:stc89c52
8位8段共陰數碼管,78LS138控制位,74HC573控制數碼管的各段,貼上電路圖。
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下面貼上DS1302的普通讀寫程序:/**************************************************************************** Name: DS1302*********** Date: 2014/12/25*********** Com: FairSun*********** LOL******************************************************************/#include <reg51.h>#include <intrins.h> //使用_nop_();sbit SCL = P1^6;sbit IO = P3^5;sbit RST = P1^7;#define H12_24 0x80 //0b1000 0000 bit7為1是12小時#define AM_PM 0x20 //在12小時模式下,bit5為1則選中了PM,在24小時模式下,為1則選中了20-24小時段#define CH 0x00 //sec設置的最高位,為0則晶振起振,為1則晶振不起振const unsigned char smg_dp_yin[ 16 ] = {0xbf, 0x86, 0xdb, 0xcf, 0xe6, 0xed, 0xfd, 0x87, 0xff, 0xef,0xf7, 0xfc, 0xb9, 0xde, 0xfb, 0xf1};//0. 1. 2. 3......f.//共陰極,顯示小數點//不顯示小數點: smg_dp_yin[x] | 0x80//共陽極顯示小數點: ~smg_dp_yin[x]//共陽極不顯示小數點: ~(smg_dp_yin[x] | 0x80)const unsigned char smg_8_pos[ 8 ] = { 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff }; //對應P20,P21,P22,高位都為1,則與的時候P2的其他位不變const unsigned char smg_sum = 8; //8位數碼管unsigned char smg_8_data[ 8 ] = { 0 };struct HMS{unsigned char hour;unsigned char min;unsigned char sec;};struct MD{unsigned char month;unsigned char date; //一月的幾日};struct YD{unsigned char year;unsigned char day; //星期幾};struct ALLDATE{struct YD yd;struct MD md;struct HMS hms; };void per_init( void );void delay_xms( unsigned int );//void Timer0_init( void );//void Timer0_server( void );void ds1302_delay( void );void Display_Time( struct ALLDATE allDate );unsigned char DecToBCD(unsigned char mData);unsigned char BCDToDec(unsigned char mData);struct ALLDATE convertToSetTime(struct ALLDATE allDate);struct ALLDATE convertToDisplayTime(struct ALLDATE allDate);void ds1302_setTime(struct ALLDATE allDate);struct ALLDATE ds1302_readTime( void );void ds1302_writeByte(unsigned char mCommand, unsigned char mData);unsigned char ds1302_readByte(unsigned char mCommand);void main(void){struct ALLDATE allDate = { {99, 4}, {12, 14}, {23, 59, 55} }; //設置時間:2099-12-14 星期4 23:59:55per_init();ds1302_setTime(allDate);while( 1 ){allDate = ds1302_readTime();Display_Time(allDate);}}/**************************************************************************函數名:void delay_xms( unsigned int x )** 功能:延時xms** 參數: 無*************************************************************************/void delay_xms( unsigned int x ){unsigned char j = 0;while( x-- ){while( (j++) < 100 );j = 0;}}/**************************************************************************函數名:void Per_init( void )** 功能:各個外設初始配置** 參數: 無*************************************************************************/void per_init( void ){P0 = 0xff;P1 = 0xff;P2 = 0xff;P3 = 0xff; }/**************************************************************************函數名:void Timer0_init( void )** 功能:定時器0初始配置** 參數: 無*************************************************************************//*void Timer0_init( void ){TMOD |= 0x01; //設置定時器0的模式為16位TH0 = ( 65536-46000 ) / 256;TL0 = (65536-46000) % 256;if( EA != 1 )EA = 1;ET0 = 1; //打開定時器0的中斷TR0 = 0; //定時器0暫停}*//**************************************************************************函數名:定時器0的中斷服務函數** 功能:裝初值** 參數: 無*************************************************************************//*void Timer0_server( void ) interrupt 1{TH0 = (65536-46000) / 256;TL0 = (65536-46000) % 256;} *//**************************************************************************函數名:void Display_Time(void)** 功能:顯示時間** 參數: 無*************************************************************************/void Display_Time(struct ALLDATE allDate) //顯示分鐘{unsigned char pos;unsigned char *pallDate = (unsigned char *)&allDate;for(pos = 0; pos <= 7; pos+=2){smg_8_data[pos] = *(pallDate+(pos>>1)) / 10 % 10;smg_8_data[pos+1] = *(pallDate+(pos>>1))%10;}/*smg_8_data[0] = allDate.yd.year / 10 % 10;smg_8_data[1] = allDate.yd.year%10;smg_8_data[2] = allDate.hms.hour / 10 % 10;smg_8_data[3] = allDate.hms.hour%10;smg_8_data[4] = allDate.hms.min / 10 % 10;smg_8_data[5] = allDate.hms.min%10;smg_8_data[6] = allDate.hms.sec / 10 % 10;smg_8_data[7] = allDate.hms.sec%10; */for( pos = 0; pos < smg_sum; pos++ ){ P2 &= 0xf8;P2 |= smg_8_pos[pos];P0 = smg_dp_yin[smg_8_data[pos]]&0x7f;delay_xms(1); } }void ds1302_delay( void ){int i;for(i = 0; i < 1; i++){_nop_();}}/**************************************************************************函數名:unsigned char DecToBCD(unsigned char mData)** 功能:10進制轉為BCD碼** 參數: unsigned char mData*************************************************************************/unsigned char DecToBCD(unsigned char mData){unsigned char BCD = 0;while(mData >= 10){mData -= 10;BCD ++; }BCD <<= 4;BCD |= mData;return BCD;}/**************************************************************************函數名:unsigned char BCDToDec(unsigned char mData)** 功能:BCD碼轉為10進制** 參數: unsigned char mData*************************************************************************/unsigned char BCDToDec(unsigned char mData){unsigned char Dec = 0;Dec = mData & 0x0f; //取得最低位mData = mData & 0x70; //剔除最高位和最低四位Dec += mData>>1; //先左移1代表*2Dec += mData>>3; //再左移3代表*8,所以總的相當于乘以10return Dec;}/*struct ALLDATE convertToSetTime(struct ALLDATE allDate){struct ALLDATE mAllDate;mAllDate.yd.year = ((allDate.yd.year/10)<<4) + (allDate.yd.year%10);mAllDate.yd.day = allDate.yd.day;mAllDate.md.month = ((allDate.md.month/10)<<4) + (allDate.md.month%10);mAllDate.md.date = ((allDate.md.date/10)<<4) + (allDate.md.date%10);mAllDate.hms.hour = H12_24 + AM_PM + ((allDate.hms.hour/10)<<4) + (allDate.hms.hour%10);mAllDate.hms.min = ((allDate.hms.min/10)<<4) + (allDate.hms.min%10);mAllDate.hms.sec = CH + ((allDate.hms.sec/10)<<4) + (allDate.hms.sec%10);return mAllDate;}struct ALLDATE convertToDisplayTime(struct ALLDATE allDate){struct ALLDATE mAllDate;mAllDate.yd.year = ((allDate.yd.year/10)>>4)*10 + (allDate.yd.year%10);mAllDate.yd.day = allDate.yd.day;mAllDate.md.month = ((allDate.md.month/10)<<4) + (allDate.md.month%10);mAllDate.md.date = ((allDate.md.date/10)<<4) + (allDate.md.date%10);mAllDate.hms.hour = H12_24 + AM_PM + ((allDate.hms.hour/10)<<4) + (allDate.hms.hour%10);mAllDate.hms.min = ((allDate.hms.min/10)<<4) + (allDate.hms.min%10);mAllDate.hms.sec = CH + ((allDate.hms.sec/10)<<4) + (allDate.hms.sec%10);return mAllDate; } *//**************************************************************************函數名:struct ALLDATE convertToSetTime(struct ALLDATE allDate)** 功能:將設置的時間轉為BCD碼** 參數: struct ALLDATE allDate*************************************************************************/struct ALLDATE convertToSetTime(struct ALLDATE allDate){unsigned char loop;struct ALLDATE mAllDate;unsigned char *pallDate = (unsigned char *)&allDate;unsigned char *pmAllDate = (unsigned char *)&mAllDate;for(loop = 0; loop <= 7; loop++){*(pmAllDate+loop) = DecToBCD(*(pallDate+loop)); }/*mAllDate.yd.year = DecToBCD(allDate.yd.year);mAllDate.yd.day = DecToBCD(allDate.yd.day);mAllDate.md.month = DecToBCD(allDate.md.month); //((allDate.md.month/10)<<4) + (allDate.md.month%10);mAllDate.md.date = DecToBCD(allDate.md.date); //((allDate.md.date/10)<<4) + (allDate.md.date%10);mAllDate.hms.hour = DecToBCD(allDate.hms.hour);//H12_24 + AM_PM + H12_24 + AM_PM + ((allDate.hms.hour/10)<<4) + (allDate.hms.hour%10);mAllDate.hms.min = DecToBCD(allDate.hms.min); //((allDate.hms.min/10)<<4) + (allDate.hms.min%10);mAllDate.hms.sec = CH + DecToBCD(allDate.hms.sec);//CH + ((allDate.hms.sec/10)<<4) + (allDate.hms.sec%10); */return mAllDate;}/**************************************************************************函數名:struct ALLDATE convertToDisplayTime(struct ALLDATE allDate)** 功能:將讀取的BCD碼轉為10進制要顯示的數據** 參數: struct ALLDATE allDate*************************************************************************/struct ALLDATE convertToDisplayTime(struct ALLDATE allDate){unsigned char loop;struct ALLDATE mAllDate;unsigned char *pallDate = (unsigned char *)&allDate;unsigned char *pmAllDate = (unsigned char *)&mAllDate;for(loop = 0; loop <= 7; loop ++){*(pmAllDate+loop) = BCDToDec(*(pallDate+loop));}/*mAllDate.yd.year = (((allDate.yd.year&0x80)>>4)*10) + BCDToDec(allDate.yd.year); //(((allDate.yd.year&0x80)>>4)*10) +mAllDate.yd.day = BCDToDec(allDate.yd.day);mAllDate.md.month = BCDToDec(allDate.md.month); //((allDate.md.month/10)<<4) + (allDate.md.month%10);mAllDate.md.date = BCDToDec(allDate.md.date); //((allDate.md.date/10)<<4) + (allDate.md.date%10);mAllDate.hms.hour = BCDToDec(allDate.hms.hour);//0x1f& H12_24 + AM_PM + ((allDate.hms.hour/10)<<4) + (allDate.hms.hour%10);mAllDate.hms.min = BCDToDec(allDate.hms.min); //((allDate.hms.min/10)<<4) + (allDate.hms.min%10);mAllDate.hms.sec = BCDToDec(allDate.hms.sec);//CH + ((allDate.hms.sec/10)<<4) + (allDate.hms.sec%10); */return mAllDate; }/**************************************************************************函數名:void ds1302_setTime(struct ALLDATE allDate)** 功能:把時間寫入到DS1302** 參數: struct ALLDATE allDate*************************************************************************/void ds1302_setTime(struct ALLDATE allDate){unsigned char loop;unsigned char *pallDate = (unsigned char *)&allDate;allDate = convertToSetTime(allDate);ds1302_writeByte(0x8e, 0x00); //control為的最高位wpfor(loop = 0; loop <= 6; loop++){ds1302_writeByte(0x8c-(loop<<1), *(pallDate+loop)); //sec }/*ds1302_writeByte(0x8e, 0x00); //control為的最高位wpds1302_writeByte(0x8c, allDate.yd.year); //yeards1302_writeByte(0x8a, allDate.yd.day); //dayds1302_writeByte(0x88, allDate.md.month); //monthds1302_writeByte(0x86, allDate.md.date); //dateds1302_writeByte(0x84, allDate.hms.hour); //hourds1302_writeByte(0x82, allDate.hms.min); //minds1302_writeByte(0x80, allDate.hms.sec); //sec */}/**************************************************************************函數名:struct ALLDATE ds1302_readTime( void )** 功能:從DS1302讀取時間信息** 參數: struct ALLDATE allDate*************************************************************************/struct ALLDATE ds1302_readTime( void ){unsigned char loop;struct ALLDATE allDate;unsigned char *pallDate = (unsigned char *)&allDate;for(loop = 0; loop <= 6; loop++){*(pallDate+loop) = ds1302_readByte(0x8d-(loop<<1)); }/*allDate.yd.year = ds1302_readByte(0x8d); //yearallDate.yd.day = ds1302_readByte(0x8b); //dayallDate.md.month = ds1302_readByte(0x89); //monthallDate.md.date = ds1302_readByte(0x87); //dateallDate.hms.hour = ds1302_readByte(0x85); //hourallDate.hms.min = ds1302_readByte(0x83); //minallDate.hms.sec = ds1302_readByte(0x81); //sec */allDate = convertToDisplayTime(allDate);return allDate; }/**************************************************************************函數名:void ds1302_writeByte(unsigned char mCommand, unsigned char mData)** 功能:往DS1302寫入一個字節** 參數: unsigned char mCommand, unsigned char mData*************************************************************************/void ds1302_writeByte(unsigned char mCommand, unsigned char mData){int loop;RST = 0;SCL = 0;ds1302_delay();RST = 1;ds1302_delay();for(loop = 0; loop < 8; loop++){IO = (mCommand>>loop)&0x01;ds1302_delay();SCL = 1;ds1302_delay();SCL = 0;ds1302_delay(); }for(loop = 0; loop < 8; loop++){IO = (mData>>loop)&0x01;ds1302_delay();SCL = 1;ds1302_delay();SCL = 0;ds1302_delay(); }RST = 0; //拉低停止數據傳輸 }/**************************************************************************函數名:unsigned char ds1302_readByte(unsigned char mCommand)** 功能:從DS1302讀取一個字節** 參數: unsigned char mCommand*************************************************************************/unsigned char ds1302_readByte(unsigned char mCommand){unsigned char loop = 0;unsigned char readData = 0;unsigned char temp = 0;RST = 1; //必須置高for(loop = 0; loop < 8; loop++){IO = (mCommand>>loop)&0x01;SCL = 1;ds1302_delay();SCL = 0; }for(loop = 0; loop < 8; loop++){temp = IO;SCL = 1;ds1302_delay(); SCL = 0;readData += (temp<<loop); }RST = 0; //拉低停止數據傳輸return readData; }總結
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