Datasheet

 2010 Microchip Technology Inc. Preliminary DS39979A-page 291
PIC18F87J72 FAMILY
EXAMPLE 22-4: WRITING AND READING AFE REGISTERS THROUGH THE MSSP
///////////////////////////////////////////////////////////////////////////////////////////////
// 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