STC12C5620AD series A/D conversion C language program

//---------------------------------------------------------------------
typedef    unsigned char   INT8U;
typedef    unsigned int    INT16U;
//---------------------------------------------------------------------
//The following selects the ADC conversion rate. Only one of them can be selected.
                       //          SPEED1 SPEED0 The time required for A/D conversion
#define AD_SPEED   0x60 //0110,0000   1      1     270 clock cycles are converted once.
                       //                         When the CPU operating frequency is 27MHz,
                       //                         The A/D conversion speed is about 100KHz
//#define AD_SPEED   0x40 //0100,0000   1      0     540 clock cycles are converted once
. //#define AD_SPEED   0x20 //0010,0000   0      1     810 clock cycles are converted once.
//#define AD_SPEED   0x00 //0000,0000   0      0     1080 clock cycles for conversion
//---------------------------------------------------------------------
void initiate_RS232 (void);         // Serial port initialization
void Send_Byte(INT8U one_byte);     // Send a byte
INT16U get_AD_result(INT8U channel);
void delay(INT8U delay_time);       // Delay function
//---------------------------------------------------------------------
void main()
{
   INT16U ADC_10bit;

   initiate_RS232();               //Baud rate = 9600

   ADC_CONTR |= 0x80;              //1000,0000 Turn on the A/D conversion power
   while(1)
   {
       Send_Byte(0xAA);
       Send_Byte(0xAA);

       ADC_10bit = get_AD_result(2); //P1.2 is the current A/D channel
       Send_Byte(ADC_10bit >> 8); //Send the high 8-bit measurement result
       delay(0x1);

       ADC_10bit = get_AD_result(3);//P1.3 is the current channel of A/D, measure and send the resultSend_Byte
       (ADC_10bit >> 8); //Send the high 8 bits of measurement resultdelay
      
       (0x30);                //Delay
   }
}
//---------------------------------------------------------------------
void delay(INT8U delay_time)        // Delay function
{
   INT16U n;
   while(delay_time--)
   {
       n = 6000;
       while(--n);
   }
}
//---------------------------------------------------------------------
void initiate_RS232 (void)          // Serial port initialization
{
   ES = 0;                         // Disable serial port interruptTMOD
   = 0x20;                    // Set T1 as baud rate generatorSCON
   = 0x50;                    // 0101,0000 8-bit data bit, no parity checkTH1
   = 0xFB;                     // 18.432MHz crystal, baud rate = 9600
   TL1 = 0xFB;
   RI = 0;
   TR1 = 1;
   ES = 1;                         // Enable serial port interrupt
}
//---------------------------------------------------------------------
void Send_Byte(INT8U one_byte)      // Send one byte
{
   TI = 0;                         // Clear the serial port send interrupt flag
   SBUF = one_byte;
   while (!TI);
   TI = 0;                         // Clear the serial port send interrupt flag
}
//---------------------------------------------------------------------
INT16U get_AD_result(INT8U channel)
{
   ADC_DATA   = 0;

   channel &= 0x07;                //0000,0111 clear high 5 bits
   ADC_CONTR = AD_SPEED;
   ADC_CONTR = 0xE0;               //1110,0000 clear ADC_FLAG, ADC_START and low 3 bits
   ADC_CONTR |= channel;           //select A/D current channel
   delay(1);                       //let input voltage reach stability
   ADC_CONTR |= 0x08;              //0000,1000 set ADCS = 1, start A/D conversion,
   while (1)                       //wait for A/D conversion to end
   {
       if (ADC_CONTR & 0x10)       //0001,0000 test whether A/D conversion is finished or not
       { break; }
   }
   ADC_CONTR &= 0xE7;              //1111,0111 clear ADC_FLAG, turn off A/D conversion,

   return (ADC_DATA<<8 | ADC_LOW2); //Return A/D 10-bit conversion result