User's Guide Analog-to-Digital Converter MSC1210

Summation/Shifter
17-23
Keil Simulator
to a LONG integer*/
long j;
j = ACR3;
j <<= 8;
j += ACR2;
j <<= 8;
j += ACR1;
j <<= 8;
j += ACR0;
return (j);
}
long read_a_to_d_result ()
{
long j;
/*Convert A/D Conversion results from the ADRESH:ADRESM:ADRESL
register string to a LONG integer ith sign extension*/
j = ADRESH;
j <<= 8;
j += ADRESM;
j <<= 8;
j += ADRESL;
j &= 0x00ffffff; //eleminate upper nibble
if (j & 0x00800000)
{//is result negative?
j |= 0x0ff000000;
}
return (j);
}
char init_a_to_d ()
{
char i, j;
/* Setup ADC */
// ADCON0 = 0x30; // Vref on 2.5V, Buff on, BOD off
ADCON0 = 0x20; // Vref on 1.25V, Buff on, BOD off
ADCON1 = 0X00;
ADCON2 = 0xFF; // decimation ratio
ADCON3 = 0x00;
ADCON1 = 0x05; // bipolar, Filter = auto, self calibration, offset, gain
//wait for the calibration to take place
printf (”\n\nCalibrating....\n”);