Microchip Technology ARD00330 データシート

 2010 Microchip Technology Inc.

DS39979A-page 291

///////////////////////////////////////////////////////////////////////////////////////////////
// STEP 4: Write to AFE registers
// Initialize the AFE by writing to PHASE, GAIN, STATUS, CONFIG1 and CONFIG2 registers.
// Below is an example. The registers can be programmed with values as required
// by the application.
///////////////////////////////////////////////////////////////////////////////////////////////

LATDbits.LATD7=0;

//Chipselect enable for Delta Sigma ADC

if (SSPSTATbits.BF==1)
Dummy_Read=SSPBUF;
SSPBUF = 0x0E;

//Address and Write command for Gain Register
// A6-A5--->00;A4-A0---->0x07;R/W---0 for write

while(!SSPSTATbits.BF);
Dummy_Read=SSPBUF;

//Dummy read to clear Buffer Full Status bit

SSPBUF =0x00;

//PHASE Register: No Delay

while(!SSPSTATbits.BF);
Dummy_Read=SSPBUF;
SSPBUF =0x04;

//Address automatically incremented GAIN Register
//CH1 gain 16, CH0 gain 1, No Boost

while(!SSPSTATbits.BF);
Dummy_Read=SSPBUF;
SSPBUF = 0xA0;

//Address automatically incremented STATUS Register
//Default values

while(!SSPSTATbits.BF);
Dummy_Read=SSPBUF;
SSPBUF = 0x10;

//Address automatically incrementedData for CONFIG1 Register
//No Dither, Other values are default

while(!SSPSTATbits.BF);
Dummy_Read=SSPBUF;
SSPBUF = 0x01;

//Address automatically incremented Data for CONFIG2 Register
//CLKEXT bit should be always programmed to 1

while(!SSPSTATbits.BF);
Dummy_Read=SSPBUF;
LATDbits.LATD7=1;

//Disable chip select after read/write of each set of registers

///////////////////////////////////////////////////////////////////////////////////////////////
// Read from AFE registers to verify; this step is optional and does not affect AFE Operation.
// As an example, only GAIN, STATUS, CONFIG1 and CONFIG2 are read.
///////////////////////////////////////////////////////////////////////////////////////////////

LATDbits.LATD7=0;

//Chip select enable for AFE

SSPBUF = 0x11;

//Address and Read command for Gain Register
// A6-A5--->00;A4-A0---->0x08;R/W---1 for read

while(!SSPSTATbits.BF);
Dummy_Read=SSPBUF;

//Dummy read to clear Buffer Full Status bit

SSPBUF =0x00;
while(!SSPSTATbits.BF);
D_S_ADC_data1=SSPBUF;

//Data from GAIN Register

SSPBUF =0x00;
while(!SSPSTATbits.BF);
D_S_ADC_data2=SSPBUF;

//Data from STATUS Register, Address automatically incremented

SSPBUF =0x00;
while(!SSPSTATbits.BF);
D_S_ADC_data3=SSPBUF;

//Data from CONFIG1 Register, Address automatically incremented

SSPBUF = 0x00;
while(!SSPSTATbits.BF);
D_S_ADC_data4=SSPBUF;

//Data from CONFIG2 Register, Address automatically incremented

LATDbits.LATD7=1;

//Disable chip select after read/write of each set of registers