[参考译文] TM4C1294NCPDT：I2C总线

int8_t user_i2c_read(uint8_t reg_addr, uint8_t *reg_data, uint32_t len, void *intf_ptr)
{
    int8_t rslt = 0; /* Return 0 for Success, non-zero for failure */
    uint8_t i = 0;

    /*
     * The parameter intf_ptr can be used as a variable to store the I2C address of the device
     */

    /*
     * Data on the bus should be like
     * |------------+---------------------|
     * | I2C action | Data                |
     * |------------+---------------------|
     * | Start      | -                   |
     * | Write      | (reg_addr)          |
     * | Stop       | -                   |
     * | Start      | -                   |
     * | Read       | (reg_data[0])       |
     * | Read       | (....)              |
     * | Read       | (reg_data[len - 1]) |
     * | Stop       | -                   |
     * |------------+---------------------|
     */


    I2CMasterSlaveAddrSet(I2C0_BASE, *(uint8_t *)intf_ptr, false);


    I2CMasterDataPut(I2C0_BASE, reg_addr);

    I2CMasterControl(I2C0_BASE,I2C_MASTER_CMD_SINGLE_SEND);
    while (I2CMasterBusy(I2C0_BASE)) {

    }


    I2CMasterSlaveAddrSet(I2C0_BASE, *(uint8_t *)intf_ptr, false);

    if ( len == 1){



        I2CMasterControl(I2C0_BASE,I2C_MASTER_CMD_SINGLE_RECEIVE);
        while (I2CMasterBusy(I2C0_BASE)) ;
        reg_data[0] = I2CMasterDataGet(I2C0_BASE);


    }else {

        I2CMasterControl(I2C0_BASE,I2C_MASTER_CMD_BURST_RECEIVE_START);
        while (I2CMasterBusy(I2C0_BASE)) ;
        reg_data[0] = I2CMasterDataGet(I2C0_BASE);

        for(i = 0 ; i < len -2 ; i++){

            I2CMasterControl(I2C0_BASE,I2C_MASTER_CMD_BURST_RECEIVE_CONT);
            while (I2CMasterBusy(I2C0_BASE)) ;
            reg_data[i+1] = I2CMasterDataGet(I2C0_BASE);

        }

        I2CMasterControl(I2C0_BASE,I2C_MASTER_CMD_BURST_RECEIVE_FINISH);
        while (I2CMasterBusy(I2C0_BASE)) ;
        reg_data[i+1] = I2CMasterDataGet(I2C0_BASE);

 return rslt;


    }