i2c slave mode

Other Parts Discussed in Thread: MSP430F2013

Dear all,

I'm working with the micro MSP430F2013  like Master and Slave, so I want to communicate there devices by I2C, I've the code for Master but I can't configure like Slave, I think that is with the register USIMST=0 rigth? but there any register like USISLV or something there?

//#include "io430.h"
#include "msp430x20x3.h"

char SLV_data = 0x00;                  
char SLV_Addr = 0x39;                  
int I2C_State = 0;                     


void main(void)
{
 volatile unsigned int i;             // Use volatile to prevent removal

  WDTCTL = WDTPW + WDTHOLD;            // Stop watchdog

  if (CALBC1_1MHZ ==0xFF || CALDCO_1MHZ == 0xFF)        
  //if (CALBC1_8MHZ==0xFD || CALDCO_8MHZ ==0xFC )
  {  
    while(1);                          
  }
  BCSCTL1 = CALBC1_1MHZ;               
  DCOCTL = CALDCO_1MHZ;

  P1OUT = 0xC0;                        
  P1REN |= 0xC0;                       
  P1DIR = 0x13;                        
  P1DIR |= 0x07;                       

  USICTL0 = USIPE6+USIPE7+USIMST+USISWRST;
  USICTL1 = USII2C+USIIE;               
  USICKCTL = USIDIV_3+USISSEL_2+USICKPL;
  USICNT |= USIIFGCC;                   
  USICTL0 &= ~USISWRST;                 
  USICTL1 &= ~USIIFG;                   
  _EINT();

  while(1)
  {
    USICTL1 |= USIIFG;                 
    LPM0;                              
    _NOP();                            
    for (i = 0; i < 5000; i++);        
  }
}

/******************************************************
// USI interrupt service routine
******************************************************/
#pragma vector = USI_VECTOR
__interrupt void USI_TXRX (void)
{
  switch(I2C_State)
    {
      case 0: // Generate Start Condition & send address to slave
              USISRL = 0x00;             // Generate Start Condition...
              USICTL0 |= USIGE+USIOE;    // Set SDA = Output and set the Latch to Transparent  
              USICTL0 &= ~USIGE;         // Set the Latch to Gated by Clock 
              USISRL = SLV_Addr ;  // Load the shift register to the transmit address, R/W = 0
              USISRL = SLV_Addr;         // transmit slv address, R/W bit = 1
              USICNT = (USICNT & 0xE0) + 0x08; // Bit counter = 8, TX Address
              I2C_State = 2;           // Go to next state: receive address (N)Ack
              break;

      case 2: // Receive Address Ack/Nack bit
              USICTL0 &= ~(USIOE + USIGE);      // SDA = input
              USICNT |= 0x01;                   // Bit counter = 1, receive (N)Ack bit
              I2C_State = 4;                    // Go to next state: check (N)Ack
              break;

      case 4: // Process Address Ack/Nack & handle data RX
              if (USISRL & 0x01)       // If Nack received...
              { // Prep Stop Condition
                USICTL0 |= USIOE;
                USISRL = 0x00;
                USICNT |=  0x01;       // Bit counter = 1, SCL high, SDA low
                I2C_State = 10;        // Go to next state: generate Stop
                P1OUT |= 0x07;         //Turn high pin 1.2(relay1)
                P1OUT |= 0x13;         // Turn high pin 1.4(relay2)
              }
              else                      // Ack received
              {                         // Receive Data from slave
                USICNT |=  0x08;       // Bit counter = 8, RX data
                I2C_State = 6;         // Go to next state: Test data and (N)Ack
                P1OUT &= ~0x07;        // pin 1.2 is low
                P1OUT &= ~0x13;        // pin 1.4 is low  
              }
              break;

      case 6: // Send Data Ack/Nack bit
              USICTL0 |= USIOE;        // SDA = output
              if (USISRL == SLV_data)  // If data valid...
              {
                USISRL = 0x00;         // Send Ack
                SLV_data++;            // Increment Slave data
                P1OUT &= ~0x07;        // pin 1.2 is low
                P1OUT &= ~0x13;        // pin 1.4 is low  
                
              //  P1OUT &= ~0x01;        // LED off
              }
              else
              {
                USISRL = 0xFF;         // Send NAck
                P1OUT |= 0x07;         //Turn high pin 1.2(relay1)
                P1OUT |= 0x13;         // Turn high pin 1.4(relay2)
            
              }
              USICNT |= 0x01;          // Bit counter = 1, send (N)Ack bit
              I2C_State = 8;           // Go to next state: prep stop
              break;

      case 8: // Prep Stop Condition
              USICTL0 |= USIOE;        // SDA = output
              USISRL = 0x00;
              USICNT |=  0x01;         // Bit counter = 1, SCL high, SDA low
              I2C_State = 10;          // Go to next state: generate Stop
              break;

      case 10: // Generate Stop Condition
              USISRL = 0x0FF;          // USISRL = 1 to release SDA
              USICTL0 |= USIGE;        // Transparent latch enabled
              USICTL0 &= ~(USIGE+USIOE);// Latch/SDA output disabled
              I2C_State = 0;           // Reset state machine for next transmission
              LPM0_EXIT;               // Exit active for next transfer
              break;
    }

  USICTL1 &= ~USIIFG;                  // Clear pending flag
}