CCS/F28M36P63C2: C28 SPI interfacing with LCD

Part Number: F28M36P63C2
Other Parts Discussed in Thread: CONTROLSUITE

Tool/software: Code Composer Studio

Hello,

I am trying to write a SPI Transfer function to write data onto an Crystalfontz OFAL1602C OLED. This is how i am writing the SPI transfer function, i am transferring 10 bits in each transfer because that's how the OLED driver WS0012 operates in spi mode.

void SPI_Transfer (Uint8 type,Uint8 value)
{
    EALLOW;
   
    GpioG1DataRegs.GPADAT.bit.GPIO19=0;  //Enable the active low slave select pin on the LCD to start communication

     if(DATA==type)          //Set the data(1)/command(0) flag
     {   
           SpiaRegs.SPITXBUF=1;  //Set MOSI high
           while(SpiaRegs.SPISTS.bit.INT_FLAG !=1) { }
           dummy5 = SpiaRegs.SPIRXBUF;
     }
     else
     {
           SpiaRegs.SPITXBUF=0;  //Pull MOSI Low
           while(SpiaRegs.SPISTS.bit.INT_FLAG !=1) { }
           dummy5 = SpiaRegs.SPIRXBUF;
     }

    //Clock it in.
     GpioG1DataRegs.GPADAT.bit.GPIO18=0;
     GpioG1DataRegs.GPADAT.bit.GPIO19=1;

    //Clear the read(1)/write(0) flag to write

       SpiaRegs.SPITXBUF=0;  // Pull MOSI Low because you're always writing to the LCD , not reading from it.
       while(SpiaRegs.SPISTS.bit.INT_FLAG !=1) { }
       dummy3 = SpiaRegs.SPIRXBUF;

    //Clock in the data
     GpioG1DataRegs.GPADAT.bit.GPIO18=0;
     GpioG1DataRegs.GPADAT.bit.GPIO18=1;

       for(mask=0x80;mask;mask>>=1)
        {
           if(mask & value)

             {
               SpiaRegs.SPITXBUF=1;       // if true, SET MOSI High
               while(SpiaRegs.SPISTS.bit.INT_FLAG !=1) { }
               dummy4 = SpiaRegs.SPIRXBUF;
           }
           else

             {
               SpiaRegs.SPITXBUF=0;                //if false, PULL MOSI low
               while(SpiaRegs.SPISTS.bit.INT_FLAG !=1) { }
               dummy5 = SpiaRegs.SPIRXBUF;
           }

             //CLOCK IT IN
             GpioG1DataRegs.GPADAT.bit.GPIO18=0;
             GpioG1DataRegs.GPADAT.bit.GPIO18=1;
           }

   // Disable the Active low Slave select pin and end communication for one cycle
       GpioG1DataRegs.GPADAT.bit.GPIO19=1;
 
       EDIS;
}

I am looking at the oscilloscope output for the SPI-A pins on the DSP board and i am getting correct outputs on the SPI-STEA signal and SPI-CLK signal. But i don't see any outputs on my MOSI pin.

What am i doing wrong?? Any suggestion or help is greatly appreciated. I have also included my spi init and config function below,

void InitSpi(void)
{
    // Initialize SPI-A

    // Set reset low before configuration changes
    // Clock polarity (0 == rising, 1 == falling)
    // 16-bit character
    //** Enable loop-back
    SpiaRegs.SPICCR.bit.SPISWRESET = 0;
    SpiaRegs.SPICCR.bit.CLKPOLARITY = 0;
    SpiaRegs.SPICCR.bit.SPICHAR = (10-1) ;
    SpiaRegs.SPICCR.bit.SPILBK = 0; //disable loopback

    // Enable master (0 == slave, 1 == master)
    // Enable transmission (Talk)
    // Clock phase (0 == normal, 1 == delayed)
    // SPI interrupts are disabled
    SpiaRegs.SPICTL.bit.MASTER_SLAVE = 1;//In Master mode
    SpiaRegs.SPICTL.bit.TALK = 1; //Enable transmission
    SpiaRegs.SPICTL.bit.CLK_PHASE = 0; //phase normal for the clock
    SpiaRegs.SPICTL.bit.SPIINTENA = 0; //Disable Spi interrupts

    // Set the baud rate
    SpiaRegs.SPIBRR = SPI_BRR; //baud rate for SPI

    // Set FREE bit
    // Halting on a breakpoint will not halt the SPI
    SpiaRegs.SPIPRI.bit.FREE = 1;

    // Release the SPI from reset
    SpiaRegs.SPICCR.bit.SPISWRESET = 1;
}

void InitSpiaGpio()
{

    EALLOW;

/* Enable internal pull-up for the selected pins */

// Pull-up enable should be set in the
// GPIO_O_PUR register in the M3 code.

/* Set qualification for selected pins to asynch only */

// This will select asynch (no qualification) for the selected pins.
// Comment out other unwanted lines.

    GpioCtrlRegs.GPAQSEL2.bit.GPIO16 = 3; // Asynch input GPIO16 (SPISIMOA)
    GpioCtrlRegs.GPAQSEL2.bit.GPIO17 = 3; // Asynch input GPIO17 (SPISOMIA)
    GpioCtrlRegs.GPAQSEL2.bit.GPIO18 = 3; // Asynch input GPIO18 (SPICLKA)
    GpioCtrlRegs.GPAQSEL2.bit.GPIO19 = 3; // Asynch input GPIO19 (SPISTEA)

//    GpioCtrlRegs.GPBQSEL2.bit.GPIO54 = 3; // Asynch input GPIO16 (SPISIMOA)
//    GpioCtrlRegs.GPBQSEL2.bit.GPIO55 = 3; // Asynch input GPIO17 (SPISOMIA)
//    GpioCtrlRegs.GPBQSEL2.bit.GPIO56 = 3; // Asynch input GPIO18 (SPICLKA)
//    GpioCtrlRegs.GPBQSEL2.bit.GPIO57 = 3; // Asynch input GPIO19 (SPISTEA)

/* Configure SPI-A pins using GPIO regs*/

// This specifies which of the possible GPIO pins will be SPI functional pins.
// Comment out other unwanted lines.

    GpioCtrlRegs.GPAMUX2.bit.GPIO16 = 1; // Configure GPIO16 as SPISIMOA
    GpioCtrlRegs.GPAMUX2.bit.GPIO17 = 1; // Configure GPIO17 as SPISOMIA
    GpioCtrlRegs.GPAMUX2.bit.GPIO18 = 1; // Configure GPIO18 as SPICLKA
    GpioCtrlRegs.GPAMUX2.bit.GPIO19 = 1; // Configure GPIO19 as SPISTEA

//    GpioCtrlRegs.GPBMUX2.bit.GPIO54 = 1; // Configure GPIO54 as SPISIMOA
//    GpioCtrlRegs.GPBMUX2.bit.GPIO55 = 1; // Configure GPIO55 as SPISOMIA
//    GpioCtrlRegs.GPBMUX2.bit.GPIO56 = 1; // Configure GPIO56 as SPICLKA
//    GpioCtrlRegs.GPBMUX2.bit.GPIO57 = 1; // Configure GPIO57 as SPISTEA

    EDIS;
}

Thank you,

Srini