Use Timer 0 to generate multiple time intervals

Use the microcontroller timer 0 to generate multiple time intervals. In the program, use timer 0 to interrupt once every 50ms, and then use global variables tt, t1, t2, t3, t4, t5 to count the number of interrupts to obtain 100ms, 1s, 2s, 4s, 8s, 16s intervals. In each timing interval, turn the LED light on and off once. The source program is as follows:
#include < AT89X51.H>
unsigned char tt,t1,t2,t3,t4,t5; //Global time interval variable
unsigned char code dispcode[]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,
0x82,0xF8,0x80,0x90}; //Seven-segment digital tube decoding table
void main(void) //Main function
{
TMOD=0x01; //Timer 0 runs in working mode 1, GATE=0, C/T=0
TH0=(65536-15536)/256; //Set the initial value of the high 8 bits of timer 0
TL0=(65536-15536)%256; //Set the initial value of the low 8 bits of timer 0
//If the machine cycle is 1μs, the count is 50000, which is equivalent to 50ms.
TR0=1; //Start timer
ET0=1; //Enable timer 0 interrupt
EA=1; //Enable total interrupt
while(1) //Infinite loop
{
if(t1>5) P2_0=0; else P2_0=1; //Blink the LED according to the time interval variable value
if(t2>10) P2_1=0; else P2_1=1;
if(t3>20) P2_2=0; else P2_2=1;
if(t4>40) P2_3=0; else P2_3=1;
if(t5>80) P2_4=0; else P2_4=1;
P1=dispcode[t4/10]; //Display the tens digit of interval variable t4
P0=dispcode[t4%10]; //Display the ones digit of interval variable t4
}}
void t0(void) interrupt 1 //Timer 0 interrupt service routine
{
TH0=(65536-15536)/256; //Set the initial value of the high 8 bits of timer 0 (3CH)
TL0=(65536-15536)%256; //Set the initial value of the low 8 bits of timer 0 (B0H)
tt++; //Every time an interrupt occurs, tt increases by 1
if(tt==2) //If tt is equal to 2, which is equivalent to 100ms, execute the following statement
{
tt=0; //Clear tt, so the count value of tt is 0---1---2 (0), each interval is 50ms
t1++;
if(t1==10){t1=0;} t2
++; if(t2==20){t2=0;} t3++; if(t3==40){t3=0;} t4++; if(t4==80){t4=0;} t5++; if(t5==160){t5=0;} P2_6=~P2_6; //Every 100ms, the LED connected to P2_6 flashes once } }