Forum Post: SPI read is not working in tm4c1230h6pm

Hi Team,

            I am using TM4C1230h6pm. I am interfacing SPI with SSt25vf016b The SPI Read is not working. The SSt25vf016b has 8 bit communication.   When i try read JeDEC_ID from serial flash i could not able read any instead i get only 0 in temp variable. I have confirmed that TI microcontroller is sending 0x9F instruction to serial flash via CRO but i could not able to read the data. Please help. Since it is blocking issue for us please help ASAP.

 void Configure_SPI(void)
{
        //
    // The SSI1 peripheral must be enabled for use.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_SSI1);
        SysCtlPeripheralEnable (SYSCTL_RCGC1_SSI1);


    //
    // For this example SSI1 is used with PortD[0:3].  The actual port and pins
    // used may be different on your part, consult the data sheet for more
    // information.  GPIO port D needs to be enabled so these pins can be used.
    // TODO: change this to whichever GPIO port you are using.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
    
        GPIOPinTypeGPIOOutput(GPIO_PORTD_BASE, GPIO_PIN_1); //SSI1Fss
        GPIOPinWrite(GPIO_PORTD_BASE, GPIO_PIN_1, GPIO_PIN_1);
        //
    // Configure the pin muxing for SSI1 functions on port D3, D2, D1, and D0.
    // 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_PD0_SSI1CLK);
    GPIOPinConfigure(GPIO_PD2_SSI1RX);
    GPIOPinConfigure(GPIO_PD3_SSI1TX);
        
        //
    // Configure and enable the SSI port for SPI master mode.  Use SSI1,
    // system clock supply, idle clock level low and active low clock in
    // freescale SPI mode, master mode, 1MHz SSI frequency, and 8-bit data.
    // For SPI mode, you can set the polarity of the SSI clock when the SSI
    // unit is idle.  You can also configure what clock edge you want to
    // capture data on.  Please reference the datasheet for more information on
    // the different SPI modes.
    //
    ROM_SSIConfigSetExpClk(SSI1_BASE, SysCtlClockGet(), SSI_FRF_MOTO_MODE_0,
                                                      SSI_MODE_MASTER, 100000, 8);
        

    //
    // Configure the GPIO settings for the SSI pins.  This function also gives
    // control of these pins to the SSI hardware.  Consult the data sheet to
    // see which functions are allocated per pin.
    // The pins are assigned as follows:
    //      PD3 - SSI1Tx
    //      PD2 - SSI1Rx
    //      PD1 - SSI1Fss
    //      PD0 - SSI1CLK
    // TODO: change this to select the port/pin you are using.
    //
        GPIOPinTypeSSI( GPIO_PORTD_BASE,GPIO_PIN_3| GPIO_PIN_2 | GPIO_PIN_1 | GPIO_PIN_0 );
        
    
    //
    // Enable the SSI1 module.
    //
    SSIEnable(SSI1_BASE);
}

uint32_t
SPIDataGet(uint32_t ui32Base)
{
        uint32_t pui32Data;

    //
    // Wait until there is data to be read.
    //
    while(!(HWREG(ui32Base + SSI_O_SR) & SSI_SR_RNE))
    {
    }

    //
    // Read data from SSI.
    //
    pui32Data = HWREG(ui32Base + SSI_O_DR);
    return (pui32Data);

unsigned long Jedec_ID_Read(void)
{
    uint32_t temp,dum_byte ;
    char buf[10];
    temp = 0;

    GPIOPinWrite(GPIO_PORTD_BASE, GPIO_PIN_1, 0);             /* enable device */
    delay_ms (100);
        
    SSIDataPut (SSI1_BASE,0x9F);         /* send JEDEC ID command (9Fh) */
    while(SSIBusy(SSI1_BASE));
    SSIDataGet (SSI1_BASE, &dum_byte);       // Dummy Byte

    temp = temp | SPIDataGet(SSI1_BASE) << 16;

    SSIDataGet (SSI1_BASE, &dum_byte);                            //Dummy Byte

    temp = temp | SPIDataGet(SSI1_BASE) << 8;

    SSIDataGet (SSI1_BASE, &dum_byte);                           //Dummy Byte
    

    temp = temp | SPIDataGet(SSI1_BASE);

    SSIDataGet (SSI1_BASE, &dum_byte);                          //Dummy Byte
    
    GPIOPinWrite(GPIO_PORTD_BASE, GPIO_PIN_1, GPIO_PIN_1);             /* disable device */
    delay_ms (100);
    sprintf (buf,"%x",temp);
    return temp;
}

If you want i can give more detail on this.

Thanks,

Shan