TI官方代码中的任务状态机

TI官方例程代码中的任务状态机用于处理各种不同的非环路控制任务，这种状态机编程对于多任务管理比较有用

// Timing sync for background loops
// Timer period definitions found in PeripheralHeaderIncludes.h
CpuTimer0Regs.PRD.all =  mSec1;		// A tasks,200000,1ms，CPU frequency=200MHz
CpuTimer1Regs.PRD.all =  mSec10;	// B tasks，2000000,10ms
CpuTimer2Regs.PRD.all =  mSec100;	// C tasks，20000000,100ms

// Tasks State-machine init
Alpha_State_Ptr = &A0;

然后在main函数里的while循环中写下如下代码：

//--------------------------------- FRAMEWORK -------------------------------------
for(;;)  //infinite loop
{
// State machine entry & exit point
//===========================================================
(*Alpha_State_Ptr)();	// jump to an Alpha state (A0,B0,...)
//===========================================================
}

在main函数之外有：

//--------------------------------- FRAMEWORK -------------------------------------
void A0(void)
{
// loop rate synchronizer for A-ta
4000
sks
if(CpuTimer0Regs.TCR.bit.TIF == 1)
{
CpuTimer0Regs.TCR.bit.TIF = 1;	// clear flag

//-----------------------------------------------------------
(*A_Task_Ptr)();		// jump to an A Task (A1,A2,A3,...)
//-----------------------------------------------------------
}

Alpha_State_Ptr = &B0;		// Comment out to allow only A tasks
}

void B0(void)
{
// loop rate synchronizer for B-tasks
if(CpuTimer1Regs.TCR.bit.TIF == 1)
{
CpuTimer1Regs.TCR.bit.TIF = 1;	// clear flag

//-----------------------------------------------------------
(*B_Task_Ptr)();		// jump to a B Task (B1,B2,B3,...)
//-----------------------------------------------------------

}

Alpha_State_Ptr = &C0;		// Allow C state tasks
}

void C0(void)
{
// loop rate synchronizer for C-tasks
if(CpuTimer2Regs.TCR.bit.TIF == 1)
{
CpuTimer2Regs.TCR.bit.TIF = 1;	// clear flag

//-----------------------------------------------------------
(*C_Task_Ptr)();		// jump to a C Task (C1,C2,C3,...)
//-----------------------------------------------------------

}

Alpha_State_Ptr = &A0;		// Back to State A0
}

任务A：

void A1(void)
{
do something
//the next time CpuTimer0 'counter' reaches Period value go to A2
A_Task_Ptr = &A2;
}

void A2(void)
{
do something
//the next time CpuTimer0 'counter' reaches Period value go to A3
A_Task_Ptr = &A3;
}

void A3(void)
{
do something
//the next time CpuTimer0 'counter' reaches Period value go to A4
A_Task_Ptr = &A4;
}

void A4(void)
{
do nothing
//the next time CpuTimer0 'counter' reaches Period value go to A1
A_Task_Ptr = &A1;
}

任务B和C的细分也类似于A，同上