// test2.c
// 定时器1中断控制两个LED交替闪烁。设置定时器1的初值，使其每隔25ms产生一次中断。
// 在中断服务程序中，每次中断对两个LED的状态进行切换，一个LED亮时另一个LED灭，
// 从而实现交替闪烁
// Timer 1 interrupt to control two LED lights to alternate.
// Set the initial value of the timer 1 to make it produce an interrupt every 25ms.
// In the interrupt service program,
// switch the state of the two LED lights every time an interrupt occurs,
// one LED light on at a time, and the other LED light off,
// thus implementing alternating flashing.

#include "homework6.h"

void test2()
{
    // Set the 38 transistors to the address.
    set38(TO_LED);
    // init the timer 1.
    TMOD = 0x9E; // set the timer 1 to mode 1.
    TH1  = 0x58; // set the timer 1 to 25ms.
    TL1  = 0x66; // set the timer 1 to 25ms.
    TR1  = 1;    // start the timer 1.
    ET1  = 1;    // enable the timer 1 interrupt.
    EA   = 1;    // enable the interrupt.
    P2   = 0xFC; // init mode: the first LED light.
    while (1) {}
}

void Timer1_ISR() interrupt 3
{
    TH1 = 0x9E; // reset the timer 1.
    TH1 = 0x58; // reset the timer 1.
    P2 ^= 0x03; // switch the state of the two LED lights.
}

void main()
{
    test2();
}