TI官方代码中的任务状态机

sick · 发表于 2020-12-7 22:29:40

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,...)
//===========================================================
}

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在main函数之外有：

1. <ul type="1" class="litype_1" style="margin-left: 14px; padding-right: 20px; padding-left: 20px; list-style: none; font-style: italic;"><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;">//--------------------------------- FRAMEWORK ------------------------------------- </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;">void A0(void) </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;">{ </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> // loop rate synchronizer for A-tasks </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> if(CpuTimer0Regs.TCR.bit.TIF == 1) </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> { </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> CpuTimer0Regs.TCR.bit.TIF = 1; // clear flag </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> //----------------------------------------------------------- </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> (*A_Task_Ptr)(); // jump to an A Task (A1,A2,A3,...) </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> //----------------------------------------------------------- </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> } </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> Alpha_State_Ptr = &B0; // Comment out to allow only A tasks </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;">} </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;">void B0(void) </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;">{ </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> // loop rate synchronizer for B-tasks </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> if(CpuTimer1Regs.TCR.bit.TIF == 1) </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> { </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> CpuTimer1Regs.TCR.bit.TIF = 1; // clear flag </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> //----------------------------------------------------------- </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> (*B_Task_Ptr)(); // jump to a B Task (B1,B2,B3,...) </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> //----------------------------------------------------------- </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> } </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> Alpha_State_Ptr = &C0; // Allow C state tasks </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;">} </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;">void C0(void) </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;">{ </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> // loop rate synchronizer for C-tasks </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> if(CpuTimer2Regs.TCR.bit.TIF == 1) </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> { </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> CpuTimer2Regs.TCR.bit.TIF = 1; // clear flag </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> //----------------------------------------------------------- </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> (*C_Task_Ptr)(); // jump to a C Task (C1,C2,C3,...) </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> //----------------------------------------------------------- </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> } </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;"> Alpha_State_Ptr = &A0; // Back to State A0 </li><li style="list-style-position: initial; list-style-image: initial; font-style: normal !important;">} 
2. </li></ul>
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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;
}

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任务B和C的细分也类似于A，同上

[经验] TI官方代码中的任务状态机

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