DK-TM4C129X: TMP100 access inconsitant values when using tiva C series I2C read

//*****************************************************************************
//
// slave_receive_int.c - Example demonstrating a simple I2C master message
//                       transmission using a slave interrupt when data is
//                       received.
//
// Copyright (c) 2010-2013 Texas Instruments Incorporated.  All rights reserved.
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//
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//   notice, this list of conditions and the following disclaimer.
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// This is part of revision 2.0.1.11577 of the Tiva Firmware Development Package.
//
//*****************************************************************************
//#define TARGET_IS_SNOWFLAKE_RA0 // part no specifies 3 added to define silicon version
// DID0 reg value is 0x100A0002, signifies Snow flake class device version
//Die revision is A2 part revision 3
#include <stdbool.h>
#include <stdint.h>
#include "inc/hw_i2c.h"
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/gpio.h"
#include "driverlib/i2c.h"
#include "driverlib/interrupt.h"
#include "driverlib/pin_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/systick.h"
#include "driverlib/uart.h"
#include "utils/uartstdio.h"


//*****************************************************************************
//
//! \addtogroup i2c_examples_list
//! <h1>Slave Receive Interrupt (slave_receive_int)</h1>
//!
//! This example shows how to configure a receive interrupt on the slave
//! module.  This includes setting up the I2C0 module for loopback mode as well
//! as configuring the master and slave modules.  Loopback mode internally
//! connects the master and slave data and clock lines together.  The address
//! of the slave module is set to a value so it can receive data from the
//! master.
//!
//! This example uses the following peripherals and I/O signals.  You must
//! review these and change as needed for your own board:
//! - I2C0 peripheral
//! - GPIO Port B peripheral (for I2C0 pins)
//! - I2C0SCL - PB2
//! - I2C0SDA - PB3
//!
//! The following UART signals are configured only for displaying console
//! messages for this example.  These are not required for operation of I2C.
//! - UART0 peripheral
//! - GPIO Port A peripheral (for UART0 pins)
//! - UART0RX - PA0
//! - UART0TX - PA1
//!
//! This example uses the following interrupt handlers.  To use this example
//! in your own application you must add these interrupt handlers to your
//! vector table.
//! - INT_I2C0 - I2C0SlaveIntHandler
//
//*****************************************************************************
#define TempSensor_SlaveAddr 0x4A
#define Config_Reg 0x01
#define Temp_reg 0x00
#define SD_Configreg 0x01
//*****************************************************************************
//
// 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 R/S 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 0x4A // slave addr for temp sensor

//*****************************************************************************
//
// Global variable to hold the I2C data that has been received.
//
//*****************************************************************************
static uint32_t g_ui32DataRx;

//*****************************************************************************
//
// This is a flag that gets set in the interrupt handler to indicate that an
// interrupt occurred.
//
//*****************************************************************************
static bool g_bIntFlag = false;

//*****************************************************************************
//
// This function sets up UART0 to be used for a console to display information
// as the example is running.
//
//*****************************************************************************
/*void
InitConsole(void)
{
    //
    // Enable GPIO port A which is used for UART0 pins.
    // TODO: change this to whichever GPIO port you are using.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

    //
    // Configure the pin muxing for UART0 functions on port A0 and A1.
    // This step is not necessary if your part does not support pin muxing.
    // TODO: change this to select the port/pin you are using.
    //
    GPIOPinConfigure(GPIO_PA0_U0RX);
    GPIOPinConfigure(GPIO_PA1_U0TX);

    //
    // Enable UART0 so that we can configure the clock.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);

    //
    // Use the internal 16MHz oscillator as the UART clock source.
    //
    UARTClockSourceSet(UART0_BASE, UART_CLOCK_PIOSC);

    //
    // Select the alternate (UART) function for these pins.
    // TODO: change this to select the port/pin you are using.
    //
    GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);

    //
    // Initialize the UART for console I/O.
    //
    UARTStdioConfig(0, 115200, 16000000);
}*/

//*****************************************************************************
//
// The interrupt handler for the for I2C0 data slave interrupt.
//
//*****************************************************************************
/*void
I2C6MasterIntHandler(void)
{
    //
    // Clear the I2C0 interrupt flag.
    //
    I2CMasterIntClear(I2C6_BASE);

    //
    // Read the data from the slave.
    //
    g_ui32DataRx = I2CMasterDataGet(I2C6_BASE);

    //
    // Set a flag to indicate that the interrupt occurred.
    //
    g_bIntFlag = true;
}*/

//*****************************************************************************
//
// Configure the I2C0 master and slave and connect them using loopback mode.
//
//*****************************************************************************
int
main(void)
{
    uint32_t ui32DataTx,error;
    volatile uint32_t pui32DataRx,pui32Configdata = 0;

    uint32_t g_ui32SysClock; // acquire sysclk value
    bool busyFlag = false;
    g_ui32SysClock = SysCtlClockFreqSet((SYSCTL_OSC_MAIN | SYSCTL_XTAL_25MHZ | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480),
                120000000);// changing to 25Mhz external crystal // Sysclk defined for 120Mhz
    SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C6);
    while(!(SysCtlPeripheralReady(SYSCTL_PERIPH_I2C6)));

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
    while(!(SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOB)));

    GPIOPinConfigure(GPIO_PB6_I2C6SCL); // pin mux
    GPIOPinConfigure(GPIO_PB7_I2C6SDA); // pin mux

    GPIOPinTypeI2C(GPIO_PORTB_BASE, GPIO_PIN_7);//    Configures pin for use as SDA
    GPIOPinTypeI2CSCL (GPIO_PORTB_BASE, GPIO_PIN_6);//    Configures pin for use as SCL

    I2CMasterInitExpClk(I2C6_BASE, g_ui32SysClock,false);// 100kbps //true); // 400kbps
    I2CMasterSlaveAddrSet(I2C6_BASE, TempSensor_SlaveAddr, false); //write slave address )0x4A

    I2CMasterEnable(I2C6_BASE); // enable master mode



    //InitConsole(); //uart init


    // read config reg
    I2CMasterSlaveAddrSet(I2C6_BASE, TempSensor_SlaveAddr, false); //write slave address )0x4A
    I2CMasterDataPut(I2C6_BASE, Config_Reg); // pointer addr config reg
    I2CMasterControl(I2C6_BASE, I2C_MASTER_CMD_SINGLE_SEND); // send pointer addr
    while(I2CMasterBusy(I2C6_BASE));
    error = I2CMasterErr(I2C6_BASE);
        if (I2CMasterErr(I2C6_BASE) != I2C_MASTER_ERR_NONE)
        {
            I2CMasterIntClear(I2C6_BASE);   // clear the interrupts if any occured.
            return false;
        }
        SysCtlDelay(50);
    SysCtlDelay(50);


    I2CMasterSlaveAddrSet(I2C6_BASE, TempSensor_SlaveAddr, true); // Config for read
    I2CMasterControl(I2C6_BASE, I2C_MASTER_CMD_SINGLE_RECEIVE);
    while(I2CMasterBusy(I2C6_BASE));
    SysCtlDelay(50);
    pui32Configdata = I2CMasterDataGet(I2C6_BASE);
    // end config reg read



    // read temp register

    I2CMasterSlaveAddrSet(I2C6_BASE, TempSensor_SlaveAddr, false); //write
    I2CMasterDataPut(I2C6_BASE, Temp_reg);
    I2CMasterControl(I2C6_BASE, I2C_MASTER_CMD_SINGLE_SEND); // points to temp register
    while(I2CMasterBusy(I2C6_BASE));
    SysCtlDelay(50);


    I2CMasterSlaveAddrSet(I2C6_BASE, TempSensor_SlaveAddr, true); // Config for read
    I2CMasterControl(I2C6_BASE, I2C_MASTER_CMD_BURST_RECEIVE_START);
    while(I2CMasterBusy(I2C6_BASE));
    SysCtlDelay(50);
    pui32DataRx = I2CMasterDataGet(I2C6_BASE); // data high
    pui32DataRx = pui32DataRx <<8;

    I2CMasterControl(I2C6_BASE, I2C_MASTER_CMD_BURST_RECEIVE_FINISH);
    while(I2CMasterBusy(I2C6_BASE))     continue;
    SysCtlDelay(50);
    pui32DataRx |= I2CMasterDataGet(I2C6_BASE); // data lower
    pui32DataRx = pui32DataRx >>4;
   // end temp read pui32DataRx has temp data



 //   read again temp data
        I2CMasterControl(I2C6_BASE, I2C_MASTER_CMD_BURST_RECEIVE_START);
        while(I2CMasterBusy(I2C6_BASE));
        SysCtlDelay(50);
        pui32DataRx = I2CMasterDataGet(I2C6_BASE);
        pui32DataRx = pui32DataRx <<8;

        I2CMasterControl(I2C6_BASE, I2C_MASTER_CMD_BURST_RECEIVE_FINISH);
        while(I2CMasterBusy(I2C6_BASE));
        SysCtlDelay(50);
        pui32DataRx |= I2CMasterDataGet(I2C6_BASE);
        pui32DataRx = pui32DataRx >>4;



    //
    // Loop forever.
    //
    while(1)
    {
    }
}