建立一个AVR单片机RTOS（8）—占先式内核(完善的服务)

//清空所有等待该信号的等待任务

}

else //当要求的信号量为独占型

{

unsigned char i;

for (i = 0; i < OS_TASKS && !(Sem[Index].OSTaskPendTbl & (0x01

if(i < OS_TASKS) //如果有任务需要

{

Sem[Index].OSTaskPendTbl &= ~(0x01

OSRdyTbl |= 0x01

}

else

{

Sem[Index].OSEventState =1; //使信号量有效

}

}

}

//从任务发送一个信号量，并进行调度

void OSTaskSemPost(unsigned char Index)

{

OSSemPost(Index);

OSSched();

}

//清除一个信号量,只对共享型的有用。

//对于独占型的信号量，在任务占用后，就交得不可以用了。

void OSSemClean(unsigned char Index)

{

Sem[Index].OSEventState =0; //要求的信号量无效

}

void TCN0Init(void) //计时器0

{

TCCR0 = 0;

TCCR0 |= (1

TIMSK |= (1

TCNT0 = 100; //置计数起始值

}

SIGNAL(SIG_OVERFLOW0)

{

IntNum++; //中断嵌套+1

sei(); //在中断中，重开中断

unsigned char i;

for(i=0;i

{

if(TCB[i].OSWaitTick && TCB[i].OSWaitTick!=0xffff)

{

TCB[i].OSWaitTick--;

if(TCB[i].OSWaitTick==0) //当任务时钟到时,必须是由定时器减时的才行

{

OSRdyTbl |= (0x01

OSCoreState|=0x02; //要求任务切换的标志位

}

}

}

TCNT0=100;

cli();

IntNum--; //中断嵌套-1

IntSwitch(); //进行任务调度

}

unsigned char __attribute__ ((progmem)) proStrA[]="Task ";

unsigned char strA[20];

SIGNAL(SIG_UART_RECV) //串口接收中断

{

strA[0]=UDR;

}

/////////////////////////////////////串口发送

unsigned char *pstr_UART_Send;

unsigned int nUART_Sending=0;

void UART_Send(unsigned char *Res,unsigned int Len) //发送字符串数组

{

if(Len>0)

{

pstr_UART_Send=Res; //发送字串的指针

nUART_Sending=Len; //发送字串的长度

UCSRB=0xB8; //发送中断使能

}

}

//SIGNAL在中断期间，其它中断禁止

SIGNAL(SIG_UART_DATA) //串口发送数据中断

{

IntNum++; //中断嵌套+1,不充许中断

if(nUART_Sending) //如果未发完

{

UDR=*pstr_UART_Send; //发送字节

pstr_UART_Send++; //发送字串的指针加1

nUART_Sending--; //等待发送的字串数减1

}

if(nUART_Sending==0) //当已经发送完

{

OSSemPost(0);

OSCoreState|=0x02; //要求任务切换的标志位

UCSRB=0x98;

}

cli(); //关发送中断

IntNum--;

IntSwitch(); //进行任务调度

}

void UARTInit() //初始化串口

{

#define fosc 8000000 //晶振8 MHZ UBRRL=(fosc/16/(baud+1))%256;

#define baud 9600 //波特率

OSCCAL=0x97; //串口波特率校正值，从编程器中读出

//UCSRB=(1

UCSRB=0x98;

//UCSRB=0x08;

UBRRL=(fosc/16/(baud+1))%256;

UBRRH=(fosc/16/(baud+1))/256;

UCSRC=(1

UCSRB=0xB8;

UDR=0;

}

//打印unsigned int到字符串中00000

void strPUT_uInt(unsigned char *Des,unsigned int i)

{

unsigned char j;

Des=Des+4;

for(j=0;j<5;j++)

{

*Des=i%10+’0’;

i=i/10;

Des--;

}

}

void strPUT_Star(unsigned char *Des,unsigned char i)

{

unsigned char j;

for(j=0;j

{

*Des++=’*’;

}

*Des++=13;

}

unsigned int strPUT_TaskState(unsigned char *Des,unsigned char TaskID,unsigned char Num)

{

//unsigned int i=0;

*(Des+4)=’0’+TaskID;

strPUT_uInt(Des+6,Num);

strPUT_Star(Des+12,TaskID);

return 12+TaskID+1;

}

void Task0()

{

unsigned int j=0;

while(1)

{

PORTB=j++;

if(OSTaskSemPend(0,0xffff))

{

unsigned int m;

m=strPUT_TaskState(strA,OSTaskRunningPrio,j);

UART_Send(strA,m);

}

OSTimeDly(200);

}

}

void Task1()

{

unsigned int j=0;

while(1)

{

PORTC=j++;

if(OSTaskSemPend(0,0xffff))

{

unsigned int m;

m=strPUT_TaskState(strA,OSTaskRunningPrio,j);

UART_Send(strA,m);

}

OSTimeDly(100);

}

}

void Task2()

{

unsigned int j=0;

while(1)

{

if(OSTaskSemPend(0,0xffff))

{

unsigned int m;

m=strPUT_TaskState(strA,OSTaskRunningPrio,j);

UART_Send(strA,m);

}

PORTD=j++;

OSTimeDly(50);

}

}

void TaskScheduler()

{

OSSched();

while(1)

{}

}

int main(void)

{

strlcpy_P(strA,proStrA,20);

UARTInit();

TCN0Init();

OSRdyTbl=0;

IntNum=0;

OSTaskCreate(Task0,&Stack[99],0);

OSTaskCreate(Task1,&Stack[199],1);

OSTaskCreate(Task2,&Stack[299],2);

OSTaskCreate(TaskScheduler,&Stack[399],OS_TASKS);

OSStartTask();

}