TMS320F28027之GPIO

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http://blog.csdn.net/w471176877/article/details/8010011

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：

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/*********************************************
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.
//===========================================================================

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/************************************
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_ */

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/************************************
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