LAUNCHXL-F28069M: F28069 I2C communication with polling and without FIFO

Hello,

I am trying to estaiblish I2C communication from one F28069 to another. I see that the slave address is 0x7900.

I have a 10kohm resistor as pull up. I have disabled interrupts and FIFO.

Using the code below I see that one byte of data is getting transferred fine but I am not able to see any clock on my SCL lines when using my logic analyzer. Would the SCL clock stop after the data transfer is over?

Does this code seem okay for starters?

Here is my code - 

#include "DSP28x_Project.h"

#include <stdint.h>

uint16_t Readi2c();

void Writei2c();

void Initi2c();

void Initi2c(void){

EALLOW;

// GpioCtrlRegs.GPBPUD.bit.GPIO32 = 0x0000;  //I am using external pull up resistors

// GpioCtrlRegs.GPBPUD.bit.GPIO33 = 0x0000;

GpioCtrlRegs.GPBQSEL1.bit.GPIO32 = 0x0003;

GpioCtrlRegs.GPBQSEL1.bit.GPIO33 = 0x0003;

GpioCtrlRegs.GPBMUX1.bit.GPIO32 = 0x0001;

GpioCtrlRegs.GPBMUX1.bit.GPIO33 = 0x0001;

EDIS;

I2caRegs.I2CMDR.all = 0x0000;                 // Keep I2C in reset before setting prescalar

I2caRegs.I2CSAR = 0x7900;        //Address of F28069

I2caRegs.I2CPSC.all = 0x0008;    // for 400kHz

I2caRegs.I2CCLKL = 20;  

I2caRegs.I2CCLKH = 10; 

I2caRegs.I2CIER.all = 0x0000; // Disable all interrupts

// I2caRegs.I2CFFTX.all = 0x6000; // Enable FIFO mode and TXFIFO

// I2caRegs.I2CFFRX.all = 0x2040; // Enable RXFIFO, clear RXFFINT,

I2caRegs.I2CMDR.all = 0x0020; // 1: Take I2C out of reset

// 0: Stop I2C when suspended

}

uint16_t Readi2c()

{

uint16_t tempdata;

I2caRegs.I2CSAR = 0x7900;

I2caRegs.I2CCNT = 0x0001;

I2caRegs.I2CMDR.all = 0x2020;       //Start in receive slave mode

while(!I2caRegs.I2CSTR.bit.RRDY); 

I2caRegs.I2CCNT = 0x0001;

I2caRegs.I2CMDR.all = 0x2C20;       // Master receive. 

I2caRegs.I2CMDR.all = 0x2820;      // Other F28069 (slave) has 0x2820 for slave mode receive

tempdata = I2caRegs.I2CDRR;

return(tempdata);

}

void Writei2c()

{

// I2caRegs.I2CMDR.all = 0x2620; //Send Start condition

I2caRegs.I2CSAR = 0x7900;

I2caRegs.I2CCNT = 0x0001;

I2caRegs.I2CDXR = 0x05; //Write one byte on bus

I2caRegs.I2CMDR.all = 0x2E20; //Send stop bit and set as master transmitter

while(!I2caRegs.I2CSTR.bit.SCD);

I2caRegs.I2CSTR.bit.SCD = 1;

}

void main()

{

uint16_t recvdata;

InitSysCtrl();    //I2C clock is initialized in this function

Initi2c();

Writei2c();      

recvdata = Readi2c(); // Line in slave F28069 to read data from F28069 master

while(1)

  {

     }

}