ADC (Analog to digital Coverter) with ARM Cortex

ADC (Analog to digital Coverter) with ARM Cortex:

Program for ADC potentiometer:

// Smpl_ADC_VR1 : use ADC7 to read Variable Resistor (on-board)
//
#include <stdio.h>                                                                                                           
#include "NUC1xx.h"
#include "SYS.h"
#include "LCD.h"

void InitADC(void)
{
    /* Step 1. GPIO initial */
    GPIOA->OFFD|=0x00800000;     //Disable digital input path
    SYS->GPAMFP.ADC7_SS21_AD6=1;         //Set ADC function
               
    /* Step 2. Enable and Select ADC clock source, and then enable ADC module */         
    SYSCLK->CLKSEL1.ADC_S = 2;    //Select 22Mhz for ADC
    SYSCLK->CLKDIV.ADC_N = 1;    //ADC clock source = 22Mhz/2 =11Mhz;
    SYSCLK->APBCLK.ADC_EN = 1;    //Enable clock source
    ADC->ADCR.ADEN = 1;            //Enable ADC module

    /* Step 3. Select Operation mode */
    ADC->ADCR.DIFFEN = 0;         //single end input
    ADC->ADCR.ADMD   = 0;         //single mode
       
    /* Step 4. Select ADC channel */
    ADC->ADCHER.CHEN = 0x80;
   
    /* Step 5. Enable ADC interrupt */
    ADC->ADSR.ADF =1;             //clear the A/D interrupt flags for safe
    ADC->ADCR.ADIE = 1;
//    NVIC_EnableIRQ(ADC_IRQn);
   
    /* Step 6. Enable WDT module */
    ADC->ADCR.ADST=1;
}

int32_t main (void)
{
    char TEXT1[16]="ADC Value:      ";   
    UNLOCKREG();
    SYSCLK->PWRCON.XTL12M_EN = 1; // enable external clock (12MHz)
    SYSCLK->CLKSEL0.HCLK_S = 0;      // select external clock (12MHz)
    LOCKREG();

    InitADC();            // initialize ADC

    init_LCD();  // initialize LCD pannel
    clear_LCD();  // clear LCD panel
    print_Line(0, "Smpl_ADC_VR1");
                                                
    while(1)
    {
        while(ADC->ADSR.ADF==0); // wait till conversion flag = 1, conversion is done
        ADC->ADSR.ADF=1;             // write 1 to clear the flag
        sprintf(TEXT1+10,"%4d",ADC->ADDR[7].RSLT); // convert ADC7 value into text
        print_Line(1, TEXT1);       // output TEXT to LCD
        DrvSYS_Delay(20000);       // delay
        ADC->ADCR.ADST=1;             // restart ADC sample
    }
}