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I2C Slave

 
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info@ckmintech.com



Joined: 16 May 2006
Posts: 39

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I2C Slave
PostPosted: Thu Nov 05, 2009 8:13 am     Reply with quote
I need to set up a slave mode I2C. The device need to send out a character according to the character the master device sends

I don't know is the i2c_write() should follow immediate after the i2c_read() or I need to wait under the master device send a read request. I want to know which function is correct.
Code:

#int_SSP
SSP_isr()
{
   int state, n;

   state = i2c_isr_state();

   if(state < 0x80) {  // Master is sending data
      n = i2c_read();
      switch (n) {
         case 0:
            i2c_write( targetID[ 0 ] );
            break;
         case 1:
            i2c_write( targetID[ 1 ] );
            break;
  }

   if(state >= 0x80)  { // Master is requesting data from slave
   }
}

OR
Code:

static int n;
#int_SSP
SSP_isr()
{
   int state;

   state = i2c_isr_state();

   if(state < 0x80) {  // Master is sending data
      n = i2c_read();
  }

   if(state >= 0x80)  { // Master is requesting data from slave
       switch (n) {
         case 0:
            i2c_write( targetID[ 0 ] );
            break;
         case 1:
            i2c_write( targetID[ 1 ] );
            break;
  }
}

Thanks for the help.

Rgds.
epitalon
Guest
PostPosted: Thu Nov 05, 2009 9:35 am     Reply with quote
2nd solution, of course
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