i2c.lst

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 127                                                          
 128                                                  //*************receive a byte *********//
 129                                                  unsigned char I2C_Receive_byte(void)
 130                                                  {
 131   1                                                      unsigned char i,da=0;
 132   1                                                      bit     a;
 133   1                                                      for(i=0;i<8;i++)
 134   1                                                      {
 135   2                                                              SDA=1;
 136   2                                                              SCL=1;
 137   2                                                              delay(3);
 138   2                                                              a=SDA;
 139   2                                                              delay(3);
 140   2                                                              SCL=0;
 141   2                                                              if(a==1)
 142   2                                                              {
 143   3                                                                      da=da<<1;
 144   3                                                                      da=da|0x01;
 145   3                                                              }
 146   2                                                              else
 147   2                                                              {
 148   3                                                                      da=da<<1;
 149   3                                                              }
 150   2                                                      }
 151   1                                                      return da;
 152   1                                              }
 153                                                                                                          
 154                                                  //**********Send n bety ,n<16,page[0-7],add[0-255].error return 0********//
 155                                                  bit I2C_Send_Nbyte(unsigned char page,unsigned char add,unsigned char *buffer,unsigned char n)
 156                                                  {
 157   1                                                      unsigned char i;
 158   1                                                              
 159   1                                                      I2C_start();                    //send start//                  
 160   1                                                      
 161   1                                                      I2C_Send_byte(0xa0|(page<<1));  //send device address//
 162   1                                                      if(I2C_Cack()==1)
 163   1                                                      {
 164   2                                                              I2C_stop();
 165   2                                                              return 0;
 166   2                                                      }
 167   1                                                      
 168   1                                                      I2C_Send_byte(add);             //send data address//
 169   1                                                      if(I2C_Cack()==1)
 170   1                                                      {
 171   2                                                              I2C_stop();
 172   2                                                              return 0;
 173   2                                                      }
 174   1                                                      
 175   1                                                      for(i=0;i<n;i++)                //send data//
 176   1                                                      {
 177   2                                                              I2C_Send_byte(buffer[i]);
 178   2                                                              if(I2C_Cack()==1)
 179   2                                                              {
C51 COMPILER V7.01  I2C                                                                    11/28/2003 11:13:40 PAGE 4   

 180   3                                                                      I2C_stop();
 181   3                                                                      return 0;
 182   3                                                              }
 183   2                                                      }
 184   1                                                      
 185   1                                                      I2C_stop();                     //send stop//
 186   1                                                      return 1;
 187   1                                              }                       
 188                                                          
 189                                                  
 190                                                  //***********receive n byte n<16,page[0-7],add[0-255],error return 0*********//
 191                                                  bit I2C_Receive_Nbyte(unsigned char page,unsigned char add,unsigned char *buffer,unsigned char n)
 192                                                  {
 193   1                                                      unsigned char i;
 194   1                                                      
 195   1                                                      I2C_start();                    //send start//                                          
 196   1                                                      
 197   1                                                      I2C_Send_byte(0xa0|(page<<1));          //send device address//
 198   1                                                      if(I2C_Cack()==1)
 199   1                                                      {
 200   2                                                              I2C_stop();
 201   2                                                              return 0;
 202   2                                                      }
 203   1                                                      
 204   1                                                      I2C_Send_byte(add);             //send data address//
 205   1                                                      if(I2C_Cack()==1)
 206   1                                                      {
 207   2                                                              I2C_stop();
 208   2                                                              return 0;
 209   2                                                      }
 210   1                                                      
 211   1                                                      I2C_stop();                     //send stop//
 212   1                                                      
 213   1                                                      I2C_start();                    //send start//
 214   1                                                      
 215   1                                                      I2C_Send_byte(0xa1|(page<<1));          //send device address read//
 216   1                                                      if(I2C_Cack()==1)
 217   1                                                      {
 218   2                                                              I2C_stop();
 219   2                                                              return 0;
 220   2                                                      }
 221   1              
 222   1                                                      for(i=0;i<n;i++)                //send data//
 223   1                                                      {
 224   2                                                              buffer[i]=I2C_Receive_byte();
 225   2                                                              if(i!=n)
 226   2                                                              {
 227   3                                                                      I2C_ack();
 228   3                                                              }
 229   2                                                              else
 230   2                                                              {
 231   3                                                                      I2C_nack();
 232   3                                                              }
 233   2                                                      }
 234   1                                                              
 235   1                                                      I2C_stop();                     //send stop//
 236   1                                                                              
 237   1                                                      return 1;
 238   1                                              }               
 239                                                                          
 240                                                  
 241                                                  //********main************//
C51 COMPILER V7.01  I2C                                                                    11/28/2003 11:13:40 PAGE 5   

 242                                                  void main(void)
 243                                                  {                                               
 244   1                                                      unsigned buffer[8],i;
 245   1                                                      SCON = 0x52;
 246   1                                                      TMOD=0x29;      
 247   1                                                      TH1=0xfd;
 248   1                                                      TL1=0xfd;                                       //** 9600 baud **//
 249   1                                                      TR1=1;                                          //** start timer 1 **//
 250   1                                                      TI=1;
 251   1                                                      EA=1;                                           //** Allow UART Int **//
 252   1                              
 253   1                                                      printf("I2Ctimer Test\n");
 254   1                                                      delay_ms(100);
 255   1                                                      
 256   1                                      /*              I2C_start();
 257   1                                                      
 258   1                                                      I2C_Send_byte(0x64);
 259   1                                                      if(I2C_Cack()==1)
 260   1                                                      {
 261   1                                                              I2C_stop();