当定时器寄存器TH0/TL0溢出时，溢出标志位TF0被置位，定时器中断

When the timer register TH0 / TL0 overflows, the overflow flag bit TF0 is set and the timer interrupt occurs. When the microcontroller switches to execute the timer interrupt, the timer overflow flag bit TF0 is cleared by hardware. Count control of variables in the interrupt sub-function to achieve counting timing.

When the timer register TH0/TL0 overflows, the overflow flag bit TF0 is placed, the timer interrupt occurs, and when the single-chip turns to perform the timer interrupt, the timer overflow flag bit TF0 is zeroed by the hardware. Count control of variables in the interrupt subfunction to achieve counting timing.

When timer register Th0 / tl0 overflows, overflow flag TF0 is set and timer interrupt occurs. When MCU turns to execute timer interrupt, timer overflow flag TF0 is cleared by hardware. In the interrupt subfunction, count the variables to realize the count timing.<br>