// File : m10_adc.c 

#include <GC80C520_PL44I.H>

#define ADC_DIVIDE_OSC_2  0
#define ADC_DIVIDE_OSC_4  1
#define ADC_DIVIDE_OSC_8  2
#define ADC_DIVIDE_OSC_16 3
#define ADC_DIVIDE_OSC_32 4
#define MAX_ADC 4

unsigned char channel;
unsigned char adc_intr;
unsigned int adc_result;
unsigned char value;

void m10_adc_clock_divide(unsigned char divide)
{
	value = ADCSEL;			
	value &= 0x1f;
	value = value + (divide << 5);
	ADCSEL = value;
}

void m10_adc_channel_selection(unsigned char adc_num)
{
	value = ADCSEL;			
	value &= ~(1 << adc_num);
	ADCSEL = value;	
}

void adc_enable()
{
	value = ADCON;			
	value |= 0x80;
	ADCON = value;	
}

void adc_disable()
{
	value = ADCON;			
	value &= 0x7f;
	ADCON = value;	
}

void adc_request()
{
	value = ADCON;			
	value |= 0x40;
	ADCON = value;	
}

void adc_clear_interrupt_flag()
{
	value = ADCON;			
	value &= 0xef;
	ADCON =  value;	
}

void m10_adc_mux_selection(unsigned char channel)
{
	value = ADCON;			
	value &= 0xf3;
	value = value + (channel << 2);
	ADCON  = value;	
}

unsigned int adc_9bit_result()
{
	unsigned int temp,temp1;
	temp = ADCON & 0x01;
	temp1 = ADCR << 1;
	temp1 += temp;
	return temp1;	
}

void adc_interrupt_enable()
{
	EADC = 1;
}

void adc_run(unsigned char channel)
{
	m10_adc_mux_selection(channel);
	adc_request();	
	while (!adc_intr);
	adc_intr = 0;
	adc_result = adc_9bit_result();
}

void enable_all_interrupt()
{
	EA = 1;
}

void port0_pullup_off()
{
	P0SEL = 0xff;
}

void adc_init()
{
	adc_intr = 0;
	port0_pullup_off();
	
	enable_all_interrupt();
	adc_interrupt_enable();	
	adc_enable();
	
	m10_adc_clock_divide(ADC_DIVIDE_OSC_2);

	for(channel=0;channel<MAX_ADC;channel++) // MAX_ADC
	{
		m10_adc_channel_selection(channel);	
	}

	for(channel=0;channel<MAX_ADC;channel++) //MAX_ADC
	{
		adc_run(channel);
	}
}

void adc_int(void) interrupt ADC_VECTOR
{
	adc_clear_interrupt_flag();
	adc_intr = 1;
}

void main()
{
	adc_init();
	while(1);
}