AD conversion program for my STC12C5410AD

#include"STC12C5410AD.h"
#define uchar unsigned char
unsigned char aa,bb;
void delay(uchar dd)
{
int x,y;
for(x=dd;x>0;x--)
for(y=100;y>0;y--);
}
unsigned char Read_ADC(unsigned char adcvcc)
{
//Set P1.0--P1.1 to a mode suitable for AD conversion
ADC_CONTR = ADC_CONTR|0x80; //1000,0000 turns on the A/D conversion power
delay(20); //20ms
ADC_CONTR = ADC_CONTR&0xE0; //1110,0000 clear ADC_FLAG, ADC_START bit and low 3 bits
ADC_CONTR = ADC_CONTR&0xf8|adcvcc; //Set the current channel number
delay(10); //Delay to stabilize the input voltage
ADC_DATA = 0; //Clear A/D conversion result register
ADC_CONTR = ADC_CONTR|0x08; //0000, 1000ADCS = 1, start conversion
do { ; } while((ADC_CONTR & 0x10)==0); //0001,0000 wait for the A/D conversion to end
ADC_CONTR = ADC_CONTR&0xE7; //1110,0111 clear the ADC_FLAG and ADC_START bits to stop A/D conversion
return ADC_DATA;
}
void main()
{
//Add the port for setting the ADC, such as)1.0, if P1.1 is set as the ADC port:
    P1M0 = 0x03; //0000, 0011 is used for the P1.x port of A/D conversion, first set to open drain
P1M1 = 0xC3; //0000, 0011P1.0--P1.1 is first set to open drain. Disconnect the internal pull-up resistor
bb=0x01;
while(1)
{
  aa=Read_ADC(1); //The first A/D conversion channel; if you want to change other channels, just change the substitution channel.
  P3=aa; //This is to display the A/D data on the LED of the P3 port.
}
}