TDC7200: UNABLE TO READ THE TDC7200 REGISTERS PROPERLY

Hello,

Can you please post some scope captures of the SPI communication lines during the improper transactions? What are the SPI settings being used, and do you have an example of some of the SPI transaction code that you are using?

Thanks,

Here's the code we're using for SPI transaction. We have used functions for reading and writing the 8 and 24 bit registers. We shall post the scope captures as soon as possible.

setupSPI()

{


    TRISBbits.RB0 = 1;					 // SDI configured as input
    TRISBbits.RB1 = 0;					 // SCLK configured as output
    TRISCbits.RC7 = 0;					 // SDO configured as output
    TRISCbits.RD6 = 0;					 // Slave select

    //SPI configuration

    SSPSTAT= 0b11000000;
    SSPCON1 =0b00100010;

}


enableSPI()

{

SSPCON1bits.SSPEN = 1; //activate SPI related pins

}


disableSPI()

{

SSPCON1bits.SSPEN = 0; //disable SPI pins

}



void SPIWrite(int value)

{

PIR1bits.SSPIF=0;

SSPBUF=value;

while(!PIR1bits.SSPIF);

PIR1bits.SSPIF=0;


}


unsigned char SPIRead8(int address)

{

RD6=0;

unsigned char data;

SSPBUF=(address & 0x1F);

while(!PIR1bits.SSPIF);

PIR1bits.SSPIF=0;

SSPBUF=0x00;

while(!PIR1bits.SSPIF);

data=SSPBUF;

PIR1bits.SSPIF=0;

RD6=1;

return data;

}



void SPIRead24(int address,unsigned char *a,unsigned char *b,unsigned char *c)
{
    RD6=0;
    PIR1bits.SSPIF=0;
    SSPBUF=(address & 0x1F);
    while(!PIR1bits.SSPIF);
    PIR1bits.SSPIF=0;
    SSPBUF=0x00;
    while(!PIR1bits.SSPIF);
    PIR1bits.SSPIF=0;
    *a = SSPBUF;
    SSPBUF=0x00;
    while(!PIR1bits.SSPIF);
    PIR1bits.SSPIF=0;
    *b = SSPBUF;
    SSPBUF=0x00;
    while(!PIR1bits.SSPIF);
    PIR1bits.SSPIF=0;
    *c = SSPBUF;
    RD6=1;
}



void main()

{


unsigned int counter=0;

unsigned char lower=0x00;

unsigned char upper=0x00;

unsigned char a,b,c;

unsigned char config1,config2;

unsigned char array[15];


	TRISBbits.RD7 = 0;					// Enable
	TRISBbits.RB2 = 1;					//Interrupt pin

	TRISD=0;
	PORTD=0;
    
    const int CONFIG1 = 0x00;           		// default 0x00
    const int CONFIG2 = 0x01;           		// default 0x40
    const int INT_STATUS = 0x02;        		// default 0x00
    const int INT_MASK = 0x03;           		// default 0x07
    const int COARSE_CNTR_OVF_H = 0x04;        // default 0xff
    const int COARSE_CNTR_OVF_L = 0x05;        // default 0xff
    const int CLOCK_CNTR_OVF_H = 0x06;         // default 0xff
    const int CLOCK_CNTR_OVF_L = 0x07;         // default 0xff
    const int CLOCK_CNTR_STOP_MASK_H = 0x08;   // default 0x00
    const int CLOCK_CNTR_STOP_MASK_L = 0x09;   // default 0x00
    
    const int TIME1 = 0x10;           		// default 0x00_0000
    const int CLOCK_COUNT1 = 0x11;             // default 0x00_0000
    const int TIME2 = 0x12;           		// default 0x00_0000
    const int CLOCK_COUNT2 = 0x13;             // default 0x00_0000
    const int TIME3 = 0x14;           		// default 0x00_0000
    const int CLOCK_COUNT3 = 0x15;             // default 0x00_0000
    const int TIME4 = 0x16;           		// default 0x00_0000
    const int CLOCK_COUNT4 = 0x17;             // default 0x00_0000
    const int TIME5 = 0x18;           		// default 0x00_0000
    const int CLOCK_COUNT5 = 0x19;             // default 0x00_0000
    const int TIME6 = 0x1A;           		// default 0x00_0000
    const int CALIBRATION1 = 0x1B;             // default 0x00_0000
    const int CALIBRATION2 = 0x1C;             // default 0x00_0000
    
    delay(2);
    RD7=0;
    delay(5);
    RD7=1;


	config1=0x03;
	config2=0x40;


while(1)
{               
    
	setupSPI();
	enableSPI();

	RD6=0;
	SPIWrite(CONFIG1 | 0x03); //configure for MODE 2 measurement
	SPIWrite(config1);
	RD6=1;

	for(int n=0;n<5;n++);

	RD6=0;
	SPIWrite(CONFIG2 | 0x40); //configure for single stop 
	SPIWrite(config2);
	RD6=1;

//reading back configuration registers
config1=SPIRead8(CONFIG1); 

config2=SPIRead8(CONFIG2);


while(INT);

delay(2);


SPIRead24(TIME1,&a,&b,&c);

array[0]=a;

array[1]=b;

array[2]=c;


SPIRead24(TIME2,&a,&b,&c);

array[3]=a;

array[4]=b;

array[5]=c;


SPIRead24(CLOCK_COUNT1,&a,&b,&c);

array[6]=a;

array[7]=b;

array[8]=c;


SPIRead24(CALIBRATION1,&a,&b,&c);

array[9]=a;

array[10]=b;

array[11]=c;


SPIRead24(CALIBRATION2,&a,&b,&c);

array[12]=a;

array[13]=b;

array[14]=c;



disableSPI();




 
}

}