extern bit ack;
//起動總線函數
extern void Start_I2c();
//結束總線函數  
extern void Stop_I2c();
//應答子函數
extern void Ack_I2c(bit a);
//字節數據發送函數
extern void  SendByte(unsigned char  c);
//有子地址發送多字節數據函數               
extern bit ISendStr(unsigned char sla,unsigned char suba,unsigned char *s,unsigned char no) ;
//無子地址發送多字節數據函數   
extern bit ISendStrExt(unsigned char sla,unsigned char *s,unsigned char no);
//無子地址讀字節數據函數               
extern unsigned char RcvByte();