usci_b_i2c_ex4_slaveTxMultiple.c

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 *    notice, this list of conditions and the following disclaimer.
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 *    notice, this list of conditions and the following disclaimer in the
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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#include "driverlib.h"
 
//*****************************************************************************
//
//*****************************************************************************
//*****************************************************************************
//
//Set the address for slave module. This is a 7-bit address sent in the
//following format:
//[A6:A5:A4:A3:A2:A1:A0:RS]
//
//A zero in the "RS" position of the first byte means that the master
//transmits (sends) data to the selected slave, and a one in this position
//means that the master receives data from the slave.
//
//*****************************************************************************
#define SLAVE_ADDRESS 0x48
//*****************************************************************************
//
//Specify SMCLK frequency
//
//*****************************************************************************
#define TXLENGTH 0x05
 
unsigned char transmitData[] = { 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
                                 0xB0, 0xB1, 0xB2, 0xB3, 0xB4};
unsigned char *transmitDataPointer;
unsigned char transmitLength = TXLENGTH;
 
void main ()
{
    //Stop WDT
    WDT_A_hold(WDT_A_BASE);
 
    //Assign I2C pins to USCI_B0
    GPIO_setAsPeripheralModuleFunctionInputPin(
        GPIO_PORT_P3,
        GPIO_PIN1 + GPIO_PIN2
        );
 
    //Initialize I2C as a slave device
    USCI_B_I2C_initSlave(USCI_B0_BASE,
        SLAVE_ADDRESS
        );
 
    //Set in transmit mode
    USCI_B_I2C_setMode(USCI_B0_BASE,
            USCI_B_I2C_TRANSMIT_MODE
        );
 
    //Enable I2C Module to start operations
    USCI_B_I2C_enable(USCI_B0_BASE);
 
    //Enable master trasmit interrupt
    USCI_B_I2C_enableInterrupt(USCI_B0_BASE,
            USCI_B_I2C_TRANSMIT_INTERRUPT + USCI_B_I2C_STOP_INTERRUPT
        );
 
 
    while (1)
    {
        transmitDataPointer = transmitData;
        transmitLength = TXLENGTH;
        //Enter low power mode 0 with interrupts enabled.
        __bis_SR_register(LPM0_bits + GIE);
 
        __no_operation();
    }
}
 
//******************************************************************************
//
//This is the USCI_B0 interrupt vector service routine.
//
//******************************************************************************
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=USCI_B0_VECTOR
__interrupt
#elif defined(__GNUC__)
__attribute__((interrupt(USCI_B0_VECTOR)))
#endif
void USCI_B0_ISR (void)
{
    switch (__even_in_range(UCB0IV,12)){
        case USCI_I2C_UCSTPIFG:
            //Exit LPM0 if data was transmitted
            __bic_SR_register_on_exit(LPM0_bits);
            break;
        case USCI_I2C_UCTXIFG:
            //Transmit data
            if (transmitLength > 0x00){
                USCI_B_I2C_slavePutData(USCI_B0_BASE,
                    *transmitDataPointer++
                    );
                transmitLength--;
            }
 
            break;
        default:
            break;
    }
}