TMS320F28027之GPIO

输入限制:

       输入限制电路设计的十分灵活，你可以通过配置GPxQSELn寄存器来选择输入限制的类型。在GPIO的输入模式中，可以配置为与SYSCLKOUT同步或者采样窗口限制。对于外设的输入，还可以配置成异步模式。

       不同步（异步输入）：此模式用于不要求同步或者本身就要异步的外设中，比如SCI，SPI和I2C。或者独立于SYSCLKOUT的ePWM触发。通用数字接口不能用此模式。

        采样窗口限制：在此模式中，输入信号首先与SYSCLKOUT同步，然后用一定的周期来确定采样信号。用3个或者6个，如果连续3个或者6个采样周期都采样到一样的电平，这认为是有效信号。采样周期通过GPACTRL寄存器设置。

 

采样周期：

能采样到的最短信号电平宽度：

 

 

 

配置步骤（参考文档SPRUFN3C）：

1.     总体规划IO口。

2.     使能或者除能上拉电阻（GPxPUD）。

ePWM模式默认除能，其他功能默认使能。模拟IO没有上拉电阻。

3.     输入采样设置（GPxCTRL、 GPxQSELn）。

4.     选择引脚功能（GPxMUXn or AIOMUXn）。

5.     如果是数字IO的话，选择方向（GPxDIR or AIODIR）。

6.     选择低功耗模式下的唤醒输入引脚（GPIOLPMSEL）。

7.     选择中断源（GPIOxINTnSEL），极性（xINTnCR）。

 

 

程序设计：

       实现板上的LED的驱动程序， LED相关IO的初始化都用同一个函数，分别提供了两种种方法改变LED的状态，一，通过一个函数实现。二、通过宏定义实现。第一种效率不高，占用程序存储空间较多，需要装载参数和调用指令，子函数里还有switch造成的跳转表等，但是可以用过同一个函数设置LED的状态，第二种效率高，通过三个调用设置三种状态，只是一个复制语句，相当于三条汇编指令。建议使用第二种，通过条件编译，保留第一种，但不编译。最后，写成两个LED.c和LED.h文件，供日后使用。

 

 

程序：

/*********************************************
    标题：LED_test.c
    软件平台：CCS v5.2
    硬件平台：C2000 LaunchPad
    主频：60M

      描述：练习gpio，测试led

      基于2802x C/C++ Header Files V1.26


    author：小船
    data：2012-09-23

    As supplied, this project is configured for "boot to SARAM"
    operation.  The 2802x Boot Mode table is shown below.

    $Boot_Table
    While an emulator is connected to your device, the TRSTn pin = 1,
    which sets the device into EMU_BOOT boot mode. In this mode, the
    peripheral boot modes are as follows:

      Boot Mode:   EMU_KEY        EMU_BMODE
                   (0xD00)	     (0xD01)
      ---------------------------------------
      Wait		 !=0x55AA           X
      I/O		   0x55AA	         0x0000
      SCI		   0x55AA	         0x0001
      Wait 	       0x55AA	         0x0002
      Get_Mode	   0x55AA	         0x0003
      SPI		   0x55AA	         0x0004
      I2C		   0x55AA	         0x0005
      OTP		   0x55AA	         0x0006
      Wait		   0x55AA	         0x0007
      Wait		   0x55AA	         0x0008
      SARAM		   0x55AA	         0x000A	  <-- "Boot to SARAM"
      Flash		   0x55AA	         0x000B
	  Wait		   0x55AA            Other

   Write EMU_KEY to 0xD00 and EMU_BMODE to 0xD01 via the debugger
   according to the Boot Mode Table above. Build/Load project,
   Reset the device, and Run example

   $End_Boot_Table
**********************************************/

#include "DSP28x_Project.h"     // Device Headerfile and Examples Include File

#define LED0 0x00000001
#define LED1 0x00000002
#define LED2 0x00000004
#define LED3 0x00000008

#define LED_on(LED_num)           GpioDataRegs.GPACLEAR.all = LED_num
#define LED_off(LED_num)          GpioDataRegs.GPASET.all = LED_num
#define LED_toggle(LED_num)       GpioDataRegs.GPATOGGLE.all = LED_num

#define config_leds_by_funtion


#ifdef config_leds_by_funtion
enum LED_action {on, off, toggle};
void LEDs(Uint32 LED_num, enum LED_action action);
#endif

// Prototype statements for functions found within this file.
void Gpio_select(void);
void LEDs_init();


void main(void)
{

// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2802x_SysCtrl.c file.
   InitSysCtrl();

// Step 2. Initalize GPIO:
// This example function is found in the DSP2802x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio();  // Skipped for this example

// For this example use the following configuration:
   Gpio_select();

// Step 3. Clear all interrupts and initialize PIE vector table:
// Disable CPU interrupts
   DINT;

// Initialize PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags
// are cleared.
// This function is found in the DSP2802x_PieCtrl.c file.
   InitPieCtrl();

// Disable CPU interrupts and clear all CPU interrupt flags:
   IER = 0x0000;
   IFR = 0x0000;

// Initialize the PIE vector table with pointers to the shell Interrupt
// Service Routines (ISR).
// This will populate the entire table, even if the interrupt
// is not used in this example.  This is useful for debug purposes.
// The shell ISR routines are found in DSP2802x_DefaultIsr.c.
// This function is found in DSP2802x_PieVect.c.
   InitPieVectTable();


// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP2802x_InitPeripherals.c
// InitPeripherals(); // Not required for this example

// Step 5. User specific code:

   LEDs_init();

   while(1)
   {
	   LEDs(LED0|LED1|LED2|LED3, off);
	   DELAY_US(1000000);
	   LEDs(LED1, on);
	   DELAY_US(1000000);
	   LEDs(LED2, toggle);
	   DELAY_US(1000000);
	   LED_toggle(LED1);
	   DELAY_US(1000000);
   }
}

void LEDs_init()
{
	EALLOW;
	//使能上拉电阻
	GpioCtrlRegs.GPAPUD.bit.GPIO0 = 1;
	GpioCtrlRegs.GPAPUD.bit.GPIO1 = 1;
	GpioCtrlRegs.GPAPUD.bit.GPIO2 = 1;
	GpioCtrlRegs.GPAPUD.bit.GPIO3 = 1;

	//选择GPIO功能
	GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 0x0;
	GpioCtrlRegs.GPAMUX1.bit.GPIO1 = 0x0;
	GpioCtrlRegs.GPAMUX1.bit.GPIO2 = 0x0;
	GpioCtrlRegs.GPAMUX1.bit.GPIO3 = 0x0;

	//方向
	GpioCtrlRegs.GPADIR.bit.GPIO0 = 1;
	GpioCtrlRegs.GPADIR.bit.GPIO1 = 1;
	GpioCtrlRegs.GPADIR.bit.GPIO2 = 1;
	GpioCtrlRegs.GPADIR.bit.GPIO3 = 1;

	EDIS;
}

#ifdef config_leds_by_funtion
void LEDs(Uint32 LED_num, enum LED_action action)
{
	switch (action)
	{
		case on:{
			GpioDataRegs.GPACLEAR.all = LED_num;
			break;
		}

		case off:{
			GpioDataRegs.GPASET.all = LED_num;
			break;
		}

		case toggle:{
			GpioDataRegs.GPATOGGLE.all = LED_num;
			break;
		}
	}
}
#endif

void Gpio_select(void)
{

    EALLOW;
	GpioCtrlRegs.GPAMUX1.all = 0x00000000;  // All GPIO
	GpioCtrlRegs.GPAMUX2.all = 0x00000000;  // All GPIO
	GpioCtrlRegs.GPBMUX1.all = 0x00000000;  // All GPIO
    GpioCtrlRegs.GPADIR.all = 0xFFFFFFFF;   // All outputs
    GpioCtrlRegs.GPBDIR.all = 0x0000000F;   // All outputs
    EDIS;

}
//===========================================================================
// No more.
//===========================================================================

/************************************
    标题：LEDs.h
    软件平台：CCS v5.2
    硬件平台：C2000 LaunchPad
    主频：60M

    author：小船
    data：2012-09-23
*************************************/
#ifndef LEDS_H_
#define LEDS_H_

#include "DSP28x_Project.h"

#define no_config_leds_by_funtion

#define LED0 0x00000001
#define LED1 0x00000002
#define LED2 0x00000004
#define LED3 0x00000008

#define LED_on(LED_num)           GpioDataRegs.GPACLEAR.all = LED_num
#define LED_off(LED_num)          GpioDataRegs.GPASET.all = LED_num
#define LED_toggle(LED_num)       GpioDataRegs.GPATOGGLE.all = LED_num


#ifdef config_leds_by_funtion
enum LED_action {on, off, toggle};
void LEDs(Uint32 LED_num, enum LED_action action);
#endif

void LEDs_init();

#endif /* LEDS_H_ */

/************************************
    标题：LEDs.c
    软件平台：CCS v5.2
    硬件平台：C2000 LaunchPad
    主频：60M

    author：小船
    data：2012-09-23
*************************************/
#include "LEDs.h"

void LEDs_init()
{
	EALLOW;
	//使能上拉电阻
	GpioCtrlRegs.GPAPUD.bit.GPIO0 = 1;
	GpioCtrlRegs.GPAPUD.bit.GPIO1 = 1;
	GpioCtrlRegs.GPAPUD.bit.GPIO2 = 1;
	GpioCtrlRegs.GPAPUD.bit.GPIO3 = 1;

	//选择GPIO功能
	GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 0x0;
	GpioCtrlRegs.GPAMUX1.bit.GPIO1 = 0x0;
	GpioCtrlRegs.GPAMUX1.bit.GPIO2 = 0x0;
	GpioCtrlRegs.GPAMUX1.bit.GPIO3 = 0x0;

	//方向
	GpioCtrlRegs.GPADIR.bit.GPIO0 = 1;
	GpioCtrlRegs.GPADIR.bit.GPIO1 = 1;
	GpioCtrlRegs.GPADIR.bit.GPIO2 = 1;
	GpioCtrlRegs.GPADIR.bit.GPIO3 = 1;

	EDIS;
}

#ifdef config_leds_by_funtion
void LEDs(Uint32 LED_num, enum LED_action action)
{
	switch (action)
	{
		case on:{
			GpioDataRegs.GPACLEAR.all = LED_num;
			break;
		}

		case off:{
			GpioDataRegs.GPASET.all = LED_num;
			break;
		}

		case toggle:{
			GpioDataRegs.GPATOGGLE.all = LED_num;
			break;
		}
	}
}
#endif