5 OS_EVENT * Sem;//声明一个信号量 6  7 OS_STK xdata Task1Stack[CPU_MAX_STK_SIZE]; 8 OS_STK xdata Task2Stack[CPU_MAX_STK_SIZE]; 9 10 void Task1(void xdata * ppdata) reentrant11 {12     ppdata =http://www.mamicode.com/ ppdata;13     while(1)14     {15         OSTimeDlyHMSM(0, 0, 2, 0);                   16         printf("\nTask1_START\n");                       17         OSSemPend(Sem,0,&err);//请求信号量18         printf("Task1_OK\n");                          19         OSSemPost(Sem);       //发送信号量20     }21 }22 23 void Task2(void xdata * ppdata) reentrant24 {25     ppdata =http://www.mamicode.com/ ppdata;26     while(1)27     {28         OSTimeDlyHMSM(0, 0, 4, 0);                29         printf("\nTask2_START\n");30         OSSemPend(Sem,0,&err);//请求信号量31         printf("Task2_OK\n");                            32         OSSemPost(Sem);       //发送信号量33     }34 }35 55 void main()56 {57     //.......     63     OSInit();                                              65     printf("SYSTEM INIT OK\n"); 67     OSTaskCreate(Task2, (void xdata *)0, &Task2Stack[0],5);68     OSTaskCreate(Task1, (void xdata *)0, &Task1Stack[0],6);69     Sem = OSSemCreate(1); //定义信号量，二值信号量70     OSStart(); 71 }