i2c.rar_i2c_keilc I2C

/*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*/ /*$$$$$$$$$$$$$$$$$$$$$$$24C01部分子程序$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*/ /*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*/ sbit SDA = P2^7; sbit SCL = P2^6; //起动24C01时序// void Start() { SCL=1; SDA=1; SDA=0; SCL=0; } //停止24C01时序// void Stop() { SDA=0; SCL=1; SDA=1; } /*;检测24C01的响应信号*/ bit ACK() { bit c; SDA=1; SCL=1; c=SDA; SCL=0; return c; } /*;往24C01发一8位数据*/ void SendChar(Uchar ch) { Uchar i; i=8; do { SDA=(ch&0x80); SCL=1; SCL=0; ch<<=1; }while(--i!=0); } /*;从24C01接收一8位数据*/ Uchar RecChar() { Uchar i,j; i=8; do { SCL=1; j=(j<<1)|SDA; SCL=0; }while(--i!=0); return j; } /*往24C01写多字节*/ void WriteBuf(Uint addr,Uchar idata *buf,Uchar count) { Uchar c; c=((*((Uchar *)&addr)))&0x02; Start(); SendChar(0xa0|c); ACK(); SendChar(addr); ACK(); do { SendChar(*buf++); ACK(); if(count!=1) { if(((++addr)&0x7)==0) { Stop(); for(c=0xff;c!=0;c--) ; c=((*((Uchar *)&addr))<<1)&0x02; Start(); SendChar(0xa0|c); ACK(); SendChar(addr); ACK(); } } else { Stop(); for(c=0xff;c!=0;c--) ; } }while(--count!=0); } /*至少读2字节*/ void ReadBuf(Uint addr,Uchar idata *buf,Uchar count) { Uchar ch; ch=((*((Uchar *)&addr))<<1)&0x02; Start(); SendChar(0xa0|ch); ACK(); SendChar(addr); ACK(); Start(); SendChar(0xa1|ch); ACK(); count--; do { *buf++=RecChar(); SDA=0; SCL=1; SCL=0; SDA=1; }while(--count!=0); *buf=RecChar(); Stop(); } /*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*/ /*$$$$$$$$$$$$$$$$$$$$$$$24C01部分子程序结束$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*/ /*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*/