TMS320F28027: Problem with Configuring SPI

Hi,

Is the data transfer happening as expected. Were you able to receive the data using polling mode?

Regards,
Veena

Hey Veena,

I changed data coming from arduino to a 16 bit number as int c = 0x00ff. And changed SPICHAR to 0. Now interrupt flag is set. Still program not entering into Interrupt Service Routine.  

We are receiving data using polling mode  but while sending 0x00ff for every 2sec we are recieving sequence of numbers 31,4095,65535.. . which are also not consistent .

Could  you throw some light on SPICHAR usage ? Also about ISR issue.

Thank you for your time and support

F28027 code:
#include "DSP28x_Project.h"

interrupt void spi_rcs_isr();

void main()
{
    InitSysCtrl();

    /*Interrupt config*/

    DINT;
    InitPieCtrl();

    IER = 0x0000;
    IFR = 0x0000;

    InitPieVectTable();

    EALLOW;

    PieVectTable.SPIRXINTA = &spi_rcs_isr;

    PieCtrlRegs.PIECTRL.bit.ENPIE =1;
    PieCtrlRegs.PIEIER1.bit.INTx1 = 1; // for spircs
    PieCtrlRegs.PIECTRL.bit.PIEVECT= 0x0D90;
    IER |=  M_INT6; // cpu interrupt 6 for spirx
    EINT;
    ERTM;

    /* GPIO pull up enable*/

    GpioCtrlRegs.GPAPUD.bit.GPIO16 = 0;
    GpioCtrlRegs.GPAPUD.bit.GPIO17 = 0;
    GpioCtrlRegs.GPAPUD.bit.GPIO18 = 0;
    GpioCtrlRegs.GPAPUD.bit.GPIO19 = 0;

    /*Qualification Select*/

    GpioCtrlRegs.GPAQSEL2.bit.GPIO16 = 3;
    GpioCtrlRegs.GPAQSEL2.bit.GPIO17 = 3;
    GpioCtrlRegs.GPAQSEL2.bit.GPIO18 = 3;
    GpioCtrlRegs.GPAQSEL2.bit.GPIO19 = 3;

    /*Setting up GPIO pins in SPI mode*/

    GpioCtrlRegs.GPAMUX2.bit.GPIO16 = 1;
    GpioCtrlRegs.GPAMUX2.bit.GPIO17 = 1;
    GpioCtrlRegs.GPAMUX2.bit.GPIO18 = 1;
    GpioCtrlRegs.GPAMUX2.bit.GPIO19 = 1;

    /* SPI config */
    SpiaRegs.SPICCR.bit.SPISWRESET = 0; //  reset
    SpiaRegs.SPICTL.bit.MASTER_SLAVE = 0; //  slave mode
    SpiaRegs.SPICCR.bit.CLKPOLARITY = 0; // data out on rising and in on falling
    SpiaRegs.SPICTL.bit.CLK_PHASE = 0; // no delay
    //SpiaRegs.SPIBRR = 127; // lowest baud rate
    SpiaRegs.SPICCR.bit.SPICHAR = 0; // 1 bit word
    SpiaRegs.SPISTS.bit.OVERRUN_FLAG = 0;
    SpiaRegs.SPISTS.bit.INT_FLAG = 0;
    SpiaRegs.SPIPRI.bit.TRIWIRE = 0;
    SpiaRegs.SPIFFRX.bit.RXFFIENA = 0;
    SpiaRegs.SPICTL.bit.OVERRUNINTENA = 1; //enable reciever overrun
    SpiaRegs.SPICTL.bit.SPIINTENA = 1; // tx and rx interrupt enable
    SpiaRegs.SPICCR.bit.SPISWRESET = 1; //release from reset

    /* data transmission */
    uint16_t data_rx =0;
    SpiaRegs.SPICTL.bit.TALK = 0; // transmission off

    while(1){
    	if(SpiaRegs.SPISTS.bit.INT_FLAG ==1){ // Waits until data rx’d
    	data_rx = (SpiaRegs.SPIRXBUF & 0x00ff);
    	}
    }

}

interrupt void spi_rcs_isr()
{
	int data_rx;
	data_rx = SpiaRegs.SPIRXBUF;
}

Arduino code:

#include <SPI.h>

void setup (void) {
   Serial.begin(115200); //set baud rate to 115200 for usart
   digitalWrite(SS, HIGH); // disable Slave Select
   SPI.begin ();
   SPI.setClockDivider(SPI_CLOCK_DIV128);//divide the clock by 8
}

void loop (void) {
   int c=0x00ff;
   digitalWrite(SS, LOW); // enable Slave Select
   SPI.transfer(c);
   Serial.print(c);
   digitalWrite(SS, HIGH);
   delay(2000);
}

Hi,

If you are able to receive the date using polling method and the issue is only regarding getting the interrupts, make sure the PIE interrupt is configured properly, make sure the pending flags (if any) in PIE and in SPI module are cleared before configuring the interrupt.

You can update the SPICHAR as per your application need, But you should make sure that teh data length is configured the same on both the master and slave devices.

Regards,
Veena

Hi,

Were you able to resolve the issue?

Regards,

Veena