Lesson_watch_dog.rar_watch

/* 题目： watchdog 日期： 2013-07-10 操作要求： F区PC2接地，PD2、3跳线接上(启用外部中断) 本例外部中断0开启定时器，外部中断1关闭定时器 晶振： 11.0592Mhz 作者： 任聚才 */ #include<reg52.h> #include<intrins.h> sfr WDTRST = 0xa6; sfr WDTRPG = 0xa7 ; unsigned char led[9] = {0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f,0xff}; static volatile unsigned char i,time_count; /* WDTPGR |= 0x00(2^14-1) 机器周期，16.3ms @Fosc = 12MHz WDTPGR |= 0x01(2^15-1) 机器周期，32.7ms @Fosc = 12MHz WDTPGR |= 0x02(2^16-1) 机器周期，65.5ms @Fosc = 12MHz WDTPGR |= 0x03(2^17-1) 机器周期，131ms @Fosc = 12MHz WDTPGR |= 0x04(2^18-1) 机器周期，262ms @Fosc = 12MHz WDTPGR |= 0x05(2^19-1) 机器周期，542ms @Fosc = 12MHz WDTPGR |= 0x06(2^20-1) 机器周期，1.05ms @Fosc = 12MHz WDTPGR |= 0x07(2^21-1) 机器周期，2.09ms @Fosc = 12MHz */ //流水灯花样定义 unsigned char code Type_PA[] = { 0xFC,0xF9,0xF3,0xE7,0xCF,0x9F,0x3F,0x7F,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, 0xE7,0xDB,0xBD,0x7E,0xBD,0xDB,0xE7,0xFF,0xE7,0xC3,0x81,0x00,0x81,0xC3,0xE7,0xFF, 0xAA,0x55,0x18,0xFF,0xF0,0x0F,0x00,0xFF,0xF8,0xF1,0xE3,0xC7,0x8F,0x1F,0x3F,0x7F, 0x7F,0x3F,0x1F,0x8F,0xC7,0xE3,0xF1,0xF8,0xFF,0x00,0x00,0xFF,0xFF,0x0F,0xF0,0xFF, 0xFE,0xFD,0xFB,0xF7,0xEF,0xDF,0xBF,0x7F,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x7F,0xBF,0xDF,0xEF,0xF7,0xFB,0xFD,0xFE, 0xFE,0xFC,0xF8,0xF0,0xE0,0xC0,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0xC0,0xE0,0xF0,0xF8,0xFC,0xFE, 0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF }; void init_time_ExternalInterrupt_watchdog(void) { EX0 = 1; //外部中断0开 EX1 = 1; //外部中断1开 IT0 = 0; //电平触发 IT1=0; //边沿触发，IT1=0表示电平触发 TMOD |= 0x01; //使用模式1，使用"|"符号可以在使用多个定时器时不受影响 TH0=0x00; //给定初值，这里使用定时器最大值从0开始计数一直到65535溢出 TL0=0x00; ET0=1; //定时器中断打开 TR0=1; //定时器开关打开 EA = 1; //全局中断开 P0 = 0; } /*------------------------------------------------ 延时子程序 ------------------------------------------------*/ void _delay_xus(unsigned int cnt) { while(--cnt); } int main(void) { init_time_ExternalInterrupt_watchdog(); for(i=0;i<sizeof(Type_PA/sizeof(Type_PA[0]));i++) //若重启，狗会从花样流水灯执行。即此处是重启标志。 { P0 = Type_PA[i]; _delay_xus(9535); } // WDTPRG = 0x07; WDTRST = 0x1e; //按手册顺序写0x1e和0xe1,激活看门狗,16.3ms WDTRST = 0xe1; while(1); return 0; } /*------------------------------------------------ 外部中断程序 要是把关门狗注释掉，再编辑烧进程序，按外部中断，会发现灯初始化后不闪烁了。因为外部中断里面把定时器关掉了 ------------------------------------------------*/ void ISR_Key0(void) interrupt 0 using 1 { TR0 = 0; } void ISR_Key1(void) interrupt 2 using 0 { TR0 = 0; // WDTRST = 0x1e; //按手册顺序写0x1e和0xe1,激活看门狗 // WDTRST = 0xe1; } /*------------------------------------------------ 定时器中断子程序 ------------------------------------------------*/ void Timer0_isr(void) interrupt 1 using 1 { TH0=(65535-10000)/256; //重新赋值,50ms TL0=(65535-10000)%0xff; time_count++; if(time_count==100) { P0 = ~P0; time_count = 0; } WDTRST = 0x1e; //按手册顺序写0x1e和0xe1,激活看门狗 WDTRST = 0xe1; }