rtccrc.c

动力环境监控系统 动力环境监控系统

#include"at89x55.h"
#include"intrins.h"

#define uchar unsigned char
#define uint  unsigned int

#define useRTC
//用到的系统资源
sbit	T_SCLK	=	P1^0;
sbit	T_IO	=	P1^1;
sbit	T_RST	=	P1^2;

//操作:先命令字节,后数据字节;写:先送数据位,后上升沿,数据位送出;读:先下降沿,读到数据位;
//是否用到它的RAM,NV(nonvolatile)掉电保存数据?
//CLOCK,RAM都设为突发模式,脉冲式电流充电,两个二极管,4k欧
//根据汇编言语改写

//写
void write_ds(uchar aa,uchar bb)//aa:commmand,b:parament
{
	uchar data i,cc;
	T_SCLK=0;		//时钟停止
	T_RST=0;
	for(i=0;i<8;i++)	//command byte
	{
		T_SCLK=0;
		cc=aa>>i&0x01;
		T_IO=cc;
		_nop_();
		T_SCLK=1;
	}
	for(i=0;i<8;i++)	//parament byte
	{
		T_SCLK=0;
		cc=bb>>i&0x01;
		T_IO=cc;
		_nop_();
		T_SCLK=1;
	}
	T_RST=1;		//时钟运行
}
void clock_write(uchar * clock_w)	//写时钟日历
{
	uchar data i,mm,nn;
	for(i=0;i<6;i++)
	{
		mm=0x8C-i*2;	//command,地址减2//年在前
		if(i)mm-=2;	//不写星期
                //nn=clock_w[i];
                nn=*clock_w++;
		nn=nn/10*16+nn%10;//parament,BCD2HEX
		write_ds(mm,nn);
	}
}
void setup_write()		//设置时钟控制,充电模式
{
	write_ds(0x8E,0);	//清写保护
	write_ds(0x90,0xAA);	//两二极管,40千欧方式充电
}

#ifdef useRTC
//读

unsigned char read_ds(uchar aa)//aa:commmand
{
	uchar data i=0,cc,dd=0;
	T_SCLK=0;		//时钟停止
	T_RST=0;
	for(i=0;i<8;i++)	//command byte
	{
		T_SCLK=0;
		cc=aa>>i&0x01;
		T_IO=cc;
		_nop_();
		_nop_();
		T_SCLK=1;
	}
	for(i=0;i<8;i++)	//read byte
	{
		T_SCLK=0;
		cc=T_IO;
		dd=dd+(cc<<i);
		T_SCLK=1;
		_nop_();
	}
	T_RST=1;		//时钟运行
	return(dd);
}

void clock_read(uchar * pp)
{
	uchar data i,mm,nn;	//读取的数据是HEX表示
	pp+=6;
	for(i=0;i<6;i++)
	{
		mm=0x81+i*2;	//command
		if(i==5)mm+=2;	//不读星期
		nn=read_ds(mm);
		nn=nn/16*10+nn%16;	//BCD2Hex
		*--pp=nn;
	}
}
#endif
code const CRCTable[256]=
{
	0x0000,0x1021,0x2042,0x3063,0x4084,0x50A5,0x60C6,0x70E7,
	0x8108,0x9129,0xA14A,0xB16B,0xC18C,0xD1AD,0xE1CE,0xF1EF,
	0x1231,0x0210,0x3273,0x2252,0x52B5,0x4294,0x72F7,0x62D6,
	0x9339,0x8318,0xB37B,0xA35A,0xD3BD,0xC39C,0xF3FF,0xE3DE,
	0x2462,0x3443,0x0420,0x1401,0x64E6,0x74C7,0x44A4,0x5485,
	0xA56A,0xB54B,0x8528,0x9509,0xE5EE,0xF5CF,0xC5AC,0xD58D,
	0x3653,0x2672,0x1611,0x0630,0x76D7,0x66F6,0x5695,0x46B4,
	0xB75B,0xA77A,0x9719,0x8738,0xF7DF,0xE7FE,0xD79D,0xC7BC,
	0x48C4,0x58E5,0x6886,0x78A7,0x0840,0x1861,0x2802,0x3823,
	0xC9CC,0xD9ED,0xE98E,0xF9AF,0x8948,0x9969,0xA90A,0xB92B,
	0x5AF5,0x4AD4,0x7AB7,0x6A96,0x1A71,0x0A50,0x3A33,0x2A12,
	0xDBFD,0xCBDC,0xFBBF,0xEB9E,0x9B79,0x8B58,0xBB3B,0xAB1A,
	0x6CA6,0x7C87,0x4CE4,0x5CC5,0x2C22,0x3C03,0x0C60,0x1C41,
	0xEDAE,0xFD8F,0xCDEC,0xDDCD,0xAD2A,0xBD0B,0x8D68,0x9D49,
	0x7E97,0x6EB6,0x5ED5,0x4EF4,0x3E13,0x2E32,0x1E51,0x0E70,
	0xFF9F,0xEFBE,0xDFDD,0xCFFC,0xBF1B,0xAF3A,0x9F59,0x8F78,
	0x9188,0x81A9,0xB1CA,0xA1EB,0xD10C,0xC12D,0xF14E,0xE16F,
	0x1080,0x00A1,0x30C2,0x20E3,0x5004,0x4025,0x7046,0x6067,
	0x83B9,0x9398,0xA3FB,0xB3DA,0xC33D,0xD31C,0xE37F,0xF35E,
	0x02B1,0x1290,0x22F3,0x32D2,0x4235,0x5214,0x6277,0x7256,
	0xB5EA,0xA5CB,0x95A8,0x8589,0xF56E,0xE54F,0xD52C,0xC50D,
	0x34E2,0x24C3,0x14A0,0x0481,0x7466,0x6447,0x5424,0x4405,
	0xA7DB,0xB7FA,0x8799,0x97B8,0xE75F,0xF77E,0xC71D,0xD73C,
	0x26D3,0x36F2,0x0691,0x16B0,0x6657,0x7676,0x4615,0x5634,
	0xD94C,0xC96D,0xF90E,0xE92F,0x99C8,0x89E9,0xB98A,0xA9AB,
	0x5844,0x4865,0x7806,0x6827,0x18C0,0x08E1,0x3882,0x28A3,
	0xCB7D,0xDB5C,0xEB3F,0xFB1E,0x8BF9,0x9BD8,0xABBB,0xBB9A,
	0x4A75,0x5A54,0x6A37,0x7A16,0x0AF1,0x1AD0,0x2AB3,0x3A92,
	0xFD2E,0xED0F,0xDD6C,0xCD4D,0xBDAA,0xAD8B,0x9DE8,0x8DC9,
	0x7C26,0x6C07,0x5C64,0x4C45,0x3CA2,0x2C83,0x1CE0,0x0CC1,
	0xEF1F,0xFF3E,0xCF5D,0xDF7C,0xAF9B,0xBFBA,0x8FD9,0x9FF8,
	0x6E17,0x7E36,0x4E55,0x5E74,0x2E93,0x3EB2,0x0ED1,0x1EF0
};

uint CrcCheck(uchar * pData,uint nDataLength)
{
	uint  xdata i,j,checksum=0;
	for(i=0;i<nDataLength;i++)
	{
		j=(checksum>>8) ^ (*pData++);
		checksum=(checksum<<8) ^ CRCTable[j];
	}
	return(checksum);
}