//////////global variable declaration start
char digit_count = 1;
unsigned char DIGIT1=1;
unsigned char DIGIT2=2;
unsigned char DIGIT3=3;
unsigned char DIGIT4=4;
unsigned char SEGMENT_CODE[11]={0xBE,0x8 4,0x3D,0xAD,0x87,0xAB,0xBB ,0x8C,0xBF,0xAF,0X40};
//////////global variable declaration end////////////

//////////output assignment start
sfr SEG_DATA at P1;
sbit  SEL_DIGIT1 at P3_0_bit;
sbit  SEL_DIGIT2 at P3_1_bit;
sbit  SEL_DIGIT3 at P3_2_bit;
sbit  SEL_DIGIT4 at P3_3_bit;

void INIT_OUTPUT()
{
SEG_DATA = 0;
SEL_DIGIT1 = 0;
SEL_DIGIT2 = 0;
SEL_DIGIT3 = 0;
SEL_DIGIT4 = 0;
}
//////////output assignment end
//////////input assignment start

//////////input assignment end
////////////////// SEVEN SEGMENT DISPLAY SATRT
void _7SEG_DISPLAY() iv IVT_ADDR_ET0 ilevel 0 ics ICS_AUTO
{
TCON.B4 = 0;        //stop TIMER0 FOR TIME COUNT
if(digit_count==1)
  {
  SEL_DIGIT1 = 1;
  SEL_DIGIT2 = 0;
  SEL_DIGIT3 = 0;
  SEL_DIGIT4 = 0;
  SEG_DATA = SEGMENT_CODE[(0B00000011 & seconds)];
  }
if(digit_count==2)
  {
  SEL_DIGIT1 = 0;
  SEL_DIGIT2 = 1;
  SEL_DIGIT3 = 0;
  SEL_DIGIT4 = 0;
  SEG_DATA = SEGMENT_CODE[(0B01110000 & seconds)>>4];
  }
if(digit_count==3)
  {
  SEL_DIGIT1 = 0;
  SEL_DIGIT2 = 0;
  SEL_DIGIT3 = 1;
  SEL_DIGIT4 = 0;
  SEG_DATA = SEGMENT_CODE[0];
  }
if(digit_count==4)
  {
  SEL_DIGIT1 = 0;
  SEL_DIGIT2 = 0;
  SEL_DIGIT3 = 0;
  SEL_DIGIT4 = 1;
  SEG_DATA = SEGMENT_CODE[0];
  }
digit_count++;
if(digit_count>4)   {
  digit_count=1;
  }
TH0=0xF0;
TL0=0;
TCON.B4 = 1;        //START TIMER1 FOR TIME COUNT
}