28335定时器0使用

ferris2005

定时器0使用

（1）定时器时钟配置，由于定时器的时钟源与系统时钟SYSCLOCK同步，详细配置可见SysCtrl.c文件；

（2）定时器分频设定；

（3）定时周期设定；

其中（1）（2）（3）可概括为InitCpuTimers();

（4）定时器启动TCR寄存器TSS，定时器中断使能TCR寄存器TIE=1；概括为ConfigCpuTimer(&CpuTimer0, 150, 500000);

     设置定时器中断向量入口地址；PieVectTable.TINT0 = &cpu_timer0_isr;

（5）定时器中断；包含（a）使能定时器中断TCR寄存器（b）IER|=M_INT1；使能连接的INT1中断；

     (c)PieCtrlRegs.PIEIER1.bit.INTx7=1;使能TINT0,1组中第7中断；（d）开中断EINT；ERTM；

（6）中断响应函数中需要：PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;

调试代码如下：

1. #include "DSP2833x_Device.h" // DSP2833x Headerfile Include File
   
2. #include "DSP2833x_Examples.h" // DSP2833x Examples Include File
   
3. 
   
4. #define LED            *(Uint16 *)0x4080
   
5. Uint16 i=0;
   
6. Uint16 valueLED=0;
   
7. // Prototype statements for functions found within this file.
   
8. interrupt void cpu_timer0_isr();
   
9. interrupt void xint1_isr(void);
   
10. 
    
11. void main(void)
    
12. {
    
13.    
    
14. // Step 1. Initialize System Control:
    
15. // PLL, WatchDog, enable Peripheral Clocks
    
16. // This example function is found in the DSP2833x_SysCtrl.c file.
    
17.    InitSysCtrl();
    
18. 
    
19. // Step 2. Initalize GPIO:
    
20. // This example function is found in the DSP2833x_Gpio.c file and
    
21. // illustrates how to set the GPIO to it's default state.
    
22. // InitGpio(); // Skipped for this example
    
23. 
    
24. 
    
25. // Step 3. Clear all interrupts and initialize PIE vector table:
    
26. // Disable CPU interrupts
    
27.    DINT;
    
28. 
    
29. // Initialize the PIE control registers to their default state.
    
30. // The default state is all PIE interrupts disabled and flags
    
31. // are cleared.
    
32. // This function is found in the DSP2833x_PieCtrl.c file.
    
33.    InitPieCtrl();
    
34. 
    
35. // Disable CPU interrupts and clear all CPU interrupt flags:
    
36.    IER = 0x0000;
    
37.    IFR = 0x0000;
    
38. 
    
39. // Initialize the PIE vector table with pointers to the shell Interrupt
    
40. // Service Routines (ISR).
    
41. // This will populate the entire table, even if the interrupt
    
42. // is not used in this example. This is useful for debug purposes.
    
43. // The shell ISR routines are found in DSP2833x_DefaultIsr.c.
    
44. // This function is found in DSP2833x_PieVect.c.
    
45.    InitPieVectTable();
    
46.     InitXintf();
    
47. // Interrupts that are used in this example are re-mapped to
    
48. // ISR functions found within this file.
    
49.    EALLOW; // This is needed to write to EALLOW protected registers
    
50.    PieVectTable.TINT0 = &cpu_timer0_isr;
    
51.    PieVectTable.XINT1=&xint1_isr;
    
52.    EDIS; // This is needed to disable write to EALLOW protected registers
    
53. 
    
54. // Step 4. Initialize the Device Peripheral. This function can be
    
55. // found in DSP2833x_CpuTimers.c
    
56.    InitCpuTimers(); // For this example, only initialize the Cpu Timers
    
57. #if (CPU_FRQ_150MHZ)
    
58. // Configure CPU-Timer 0 to interrupt every 500 milliseconds:
    
59. // 150MHz CPU Freq, 50 millisecond Period (in uSeconds)
    
60. //定时周期计算150/sysclk*500000
    
61.    ConfigCpuTimer(&CpuTimer0, 150, 500000);
    
62. #endif
    
63. #if (CPU_FRQ_100MHZ)
    
64. // Configure CPU-Timer 0 to interrupt every 500 milliseconds:
    
65. // 100MHz CPU Freq, 50 millisecond Period (in uSeconds)
    
66.    ConfigCpuTimer(&CpuTimer0, 100, 500000);
    
67. #endif
    
68. 
    
69. // To ensure precise timing, use write-only instructions to write to the entire register. Therefore, if any
    
70. // of the configuration bits are changed in ConfigCpuTimer and InitCpuTimers (in DSP2833x_CpuTimers.h), the
    
71. // below settings must also be updated.
    
72.     //使能定时器中断和启动定时器，对应寄存器为TCR=1和TSS=0
    
73.    CpuTimer0Regs.TCR.all = 0x4001; // Use write-only instruction to set TSS bit = 0
    
74. 
    
75. // Step 5. User specific code, enable interrupts:
    
76. 
    
77. // Configure GPIO0 as a GPIO output pin
    
78.    EALLOW;
    
79.    GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 0;
    
80.    GpioCtrlRegs.GPADIR.bit.GPIO0 = 1;
    
81.    EDIS;
    
82. 
    
83.    // Configure GPIO31 as a GPIO input pin
    
84.    EALLOW;
    
85.    GpioCtrlRegs.GPAMUX2.bit.GPIO31 = 0;//控制寄存器，控制IO工作方式
    
86.    GpioCtrlRegs.GPADIR.bit.GPIO31 = 0;//方向控制寄存器
    
87.    GpioCtrlRegs.GPAQSEL2.bit.GPIO31=0;//配置采样周期，判断IO管脚状态避免噪声
    
88.    EDIS;
    
89. 
    
90.    // GPIO31 is XINT1
    
91.    EALLOW;//数据手册PIE&GPIO，pp101，00000对应GPIO0
    
92.    GpioIntRegs.GPIOXINT1SEL.bit.GPIOSEL = 11111; // Xint1 is GPIO31
    
93.    EDIS;
    
94. 
    
95.    // Enable XINT1
    
96.    XIntruptRegs.XINT1CR.bit.ENABLE = 1; // Enable Xint1
    
97. 
    
98. // Enable CPU INT1 which is connected to CPU-Timer 0:
    
99.    IER |= M_INT1;
    
100. 
     
101. // Enable TINT0 in the PIE: Group 1 interrupt 7
     
102.    PieCtrlRegs.PIEIER1.bit.INTx7 = 1;
     
103. 
     
104. // Enable global Interrupts and higher priority real-time debug events:
     
105.    EINT; // Enable Global interrupt INTM
     
106.    ERTM; // Enable Global realtime interrupt DBGM
     
107. 
     
108. // Step 6. IDLE loop. Just sit and loop forever (optional):
     
109.    for(;;);
     
110. }
     
111. 
     
112. 
     
113. interrupt void cpu_timer0_isr()
     
114. {
     
115.        valueLED = 3 - valueLED;
     
116.     LED = valueLED;
     
117.    CpuTimer0.InterruptCount++;
     
118.    GpioDataRegs.GPATOGGLE.bit.GPIO0 = 1; // 取反，Toggle GPIO32 once per 500 milliseconds
     
119.    // Acknowledge this interrupt to receive more interrupts from group 1
     
120.    PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;
     
121. }
     
122. 
     
123. interrupt void xint1_isr(void)
     
124. {
     
125.     i++;
     
126.     // Acknowledge this interrupt to get more from group 1
     
127.     PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;
     
128. 
     
129. }
     
130. 
     
131. 
     
132. //===========================================================================
     
133. // No more.
     
134. //===========================================================================