////               Driver routines for the ADS8344 chip

#define AD1_CS    PIN_D4
#define AD2_CS    PIN_D5
#define ADC_BUSY  PIN_D3
#define ADC_DIN   PIN_D1
#define ADC_DOUT  PIN_D2
#define ADC_DCLK  PIN_D0


void write_adc_byte(byte data) {
   byte i;

   for(i=1;i<=8;++i) {
      output_low(ADC_DCLK);
      output_bit(ADC_DIN, shift_left(&data,1,0));
      output_high(ADC_DCLK);
   }
   output_low(ADC_DCLK);
}


long int read_adc_word() {
   byte i;
   long data;

   while (  input(ADC_BUSY)   )  {
      output_high(ADC_DCLK);
      output_low(ADC_DCLK);
   }

   for(i=1;i<=16;++i) {
      output_low(ADC_DCLK);
      delay_cycles(50);
      output_high(ADC_DCLK);
      shift_left(&data,2,input(ADC_DOUT));
   }
   return data;
}



long read_adc_value(byte ch) {
        long value;

   if (ch<8) output_low(AD1_CS); else output_low(AD2_CS);

   switch(ch)  {
      case 0 : write_adc_byte(0x87);
      break;
      case 1 : write_adc_byte(0xC7);
      break;
      case 2 : write_adc_byte(0x97);
      break;
      case 3 : write_adc_byte(0xD7);
      break;
      case 4 : write_adc_byte(0xA7);
      break;
      case 5 : write_adc_byte(0xE7);
      break;
      case 6 : write_adc_byte(0xB7);
      break;
      case 7 : write_adc_byte(0xF7);
      break;
   }
	value=read_adc_word();

   if (ch<8) output_high(AD1_CS); else output_high(AD2_CS);

	return value;
}