#include "LPC23xx.h"                        /* LPC23xx definitions */
#include "type.h"
#include "adc.h"

volatile DWORD ADC0Value[ADC_NUM];
volatile DWORD ADC0IntDone = 0;


/*****************************************************************************
** Function name:        ADCInit
**
** Descriptions:        initialize ADC channel
**
** parameters:            ADC clock rate
** Returned value:        true or false
**
*****************************************************************************/
ADC_INIT( DWORD ADC_Clk )
{
  /* Enable CLOCK into ADC controller */
  PCONP |= (1 << 12);


  AD0CR = ( 0x01 << 0 ) |     /* SEL=1,select channel 0~7 on ADC0 */
        ( ( 18000000 / ADC_Clk - 1 ) << 8 ) |  /* CLKDIV = Fpclk / 1000000 - 1 */
        ( 0 << 16 ) |         /* BURST = 0, no BURST, software controlled */
        ( 0 << 17 ) |          /* CLKS = 0, 11 clocks/10 bits */
        ( 1 << 21 ) |          /* PDN = 1, normal operation */
        ( 0 << 22 ) |          /* TEST1:0 = 00 */
        ( 0 << 24 ) |          /* START = 0 A/D conversion stops */
        ( 0 << 27 );        /* EDGE = 0 (CAP/MAT singal falling,trigger A/D conversion) */

  
}

/*****************************************************************************
** Function name:        ADC0Read
**
** Descriptions:        Read ADC0 channel
**
** parameters:            Channel number
** Returned value:        Value read, if interrupt driven, return channel #
**
*****************************************************************************/
DWORD ADC_READ( BYTE channelNum )
{

  DWORD regVal, ADC_Data;
/* channel number is 0 through 7 */
  if ( channelNum >= ADC_NUM )
  {
    channelNum = 0;        /* reset channel number to 0 */
  }
  AD0CR &= 0xFFFFFF00;
  AD0CR |= (1 << 24) | (1 << channelNum);    
                /* switch channel,start A/D convert */

  while ( 1 )            /* wait until end of A/D convert */
  {
    regVal = *(volatile unsigned long *)(AD0_BASE_ADDR
            + ADC_OFFSET + ADC_INDEX * channelNum);
    /* read result of A/D conversion */
    if ( regVal & ADC_DONE )
    {
      break;
    }
  }    
        
  AD0CR &= 0xF8FFFFFF;    /* stop ADC now */    

  ADC_Data = ( regVal >> 6 ) & 0x3FF;
  return ( ADC_Data );    /* return A/D conversion value */

}