f28027 and cc2520

Hi,

my name is Davide Marchei and I bought the CC2520 EMK. 

I should connect a F28027 with CC2520 via SPI. I connected the RESETn and VREG_EN pins of the CC2520 to VDD. I connected two devices in 4-wire mode. 

I'm trying to ping with the CC2520 by sending a byte with all 0, in order to receive the status of the RF, but I get no response.

The GPIO ports configuration of the F28027 is:

GpioCtrlRegs.GPAMUX2.bit.GPIO16 = 1; // 0=GPIO,  1=SPISIMO-A,  2=Resv,  3=TZ2

GpioCtrlRegs.GPADIR.bit.GPIO16 = 1; // 1=OUTput,  0=INput 

//--------------------------------------------------------------------------------------

GpioCtrlRegs.GPAMUX2.bit.GPIO17 = 1; // 0=GPIO,  1=SPISOMI-A,  2=Resv,  3=TZ3

GpioCtrlRegs.GPADIR.bit.GPIO17 = 0; // 1=OUTput,  0=INput 

//--------------------------------------------------------------------------------------

GpioCtrlRegs.GPAMUX2.bit.GPIO18 = 1; // 0=GPIO,  1=SPICLK-A,  2=SCITX-A,  3=XCLKOUT

GpioCtrlRegs.GPADIR.bit.GPIO18 = 1; // 1=OUTput,  0=INput 

GpioDataRegs.GPASET.bit.GPIO18 = 1; // uncomment if --> Set High initially

//--------------------------------------------------------------------------------------

GpioCtrlRegs.GPAMUX2.bit.GPIO19 = 1; // 0=GPIO,  1=SPISTE-A,  2=SCIRX-A,  3=ECAP1

GpioCtrlRegs.GPADIR.bit.GPIO19 = 1; // 1=OUTput,  0=INput 

The SPI configuration is:

EALLOW;

  SpiaRegs.SPICCR.bit.SPISWRESET = 0;

  SpiaRegs.SPICCR.bit.SPICHAR = 7;

  SpiaRegs.SPICCR.bit.SPILBK = 0; 

  SpiaRegs.SPICCR.bit.CLKPOLARITY = 0;

  SpiaRegs.SPICTL.bit.TALK = 1;     

  SpiaRegs.SPICTL.bit.MASTER_SLAVE = 1;

  SpiaRegs.SPICTL.bit.CLK_PHASE = 0;

  SpiaRegs.SPIPRI.bit.FREE = 1;         

  SpiaRegs.SPIBRR = 126;   

  SpiaRegs.SPIFFCT.all= 0;

  SpiaRegs.SPIPRI.bit.TRIWIRE=0;   

  SpiaRegs.SPICCR.bit.SPISWRESET = 1; 

  EDIS;

The code that I use to send and receive is the following:

//Send

if(cmd==1){

if (SpiaRegs.SPISTS.bit.BUFFULL_FLAG!= 1) {       

SpiaRegs.SPITXBUF = dataTX;// non-FIFO mode

      null = SpiaRegs.SPIRXBUF;

      cmd=0;

    }}

//Receive

if (SpiaRegs.SPISTS.bit.INT_FLAG == 1) {

dataRX = SpiaRegs.SPIRXBUF;

}

where: 

char dataTX;

char dataRX;

char null;

char cmd;

The communication must be 8-bit or 16 bit? Create a problem that the SPIRXBUF register of SPI is 16 bit, while the commands that should receive the RF is 8 bits?! There is more detailed material on communication between the F28027 (or others of the same family) with CC2520?!

Regards.

Davide Marchei