SPI Problem with TMS320F28027

Other Parts Discussed in Thread: TMS320F28027, CC2500

Hello everybody

I try to connect the CC2500 to my TMS320F28027. So i set up the SPI Interface and it works already. For example i can change the frequency of the CC2500.

Now i need to read out a register value of the CC2500. My code looks like this:

char CC2500_SPIReadReg(char addr)
{
    Uint16 i;
    char x;                                                                                        /* Return variable */
   
    i = (addr | CC2500_READ_SINGLE);                                 /* Add Single Read to Register address */
    while (SpiaRegs.SPISTS.bit.BUFFULL_FLAG == 1)       /* Wait for SPITXBUF is free */
    {
    }
    SpiaRegs.SPITXBUF = (i<<8);                                            /* Send Register address */
    while (SpiaRegs.SPISTS.bit.BUFFULL_FLAG == 1)      /* Wait for SPITXBUF is free */
    {
    }
    SpiaRegs.SPITXBUF = 0x00;                                              /* Send dummy data */
    CC2500_Wait(500);
    x = SpiaRegs.SPIRXBUF;                                                    /* Read RXBUF */
    return x;                                                                                    /* Return RXBUF */
}

It works fine and gives me the correct register value back. My Problem is now that i have to use the CC2500_Wait function. If i change the data rate the Delay time has to be changed also. So i want to realize it by using the Flags in the SPI Status Register.

My Code looks like this now:

char CC2500_SPIReadReg(char addr)
{
    Uint16 i;
    char x;                                                                                     /* Return variable */
   
    i = (addr | CC2500_READ_SINGLE);                               /* Add Single Read to Register address */
    while (SpiaRegs.SPISTS.bit.BUFFULL_FLAG == 1)     /* Wait for SPITXBUF is free */
    {
    }
    SpiaRegs.SPITXBUF = (i<<8);                                           /* Send Register address */
    while (SpiaRegs.SPISTS.bit.BUFFULL_FLAG == 1)    /* Wait for SPITXBUF is free */
    {
    }
    x = SpiaRegs.SPIRXBUF;                                                  /* Read RXBUF to clear INT_FLAG */
    SpiaRegs.SPISTS.bit.OVERRUN_FLAG = 1;
    SpiaRegs.SPITXBUF = 0x00;                                           /* Send dummy data */
    while (SpiaRegs.SPISTS.bit.INT_FLAG == 0)               /* Wait for Tx to finish */
    {
    }
    x = SpiaRegs.SPIRXBUF;                                                 /* Read RXBUF */
    return x;                                                                                 /* Return RXBUF */
}

With this code i don't get the right value back. I think when i read the SPIRXBUF the INT_Flag is cleared and set again when the next data is placed in the SPIRXBUF. But it seems that my while (SpiaRegs.SPISTS.bit.INT_FLAG == 0) doesn't wait for the new data. After i called the function i see that in the RXBUF is the correct register value but in the x variable is the dummy data. So i read out the RXBUF to soon. If i use breakpoints inside the function it gives me the correct register value back.

Can somebody tell me my fault? Do i use the wrong flags?