Pulse generation using GPIO and CPU timer interrupt-F28335

// TI File $Revision: /main/3 $
// Checkin $Date: June 23, 2010   09:28:07 $
//###########################################################################
//
// FILE:    Example_2833xGpioToggle.c
//
// TITLE:   DSP2833x Device GPIO toggle test program. 
//
// ASSUMPTIONS:
//
//    This program requires the DSP2833x header files.  
//
//    ALL OF THE I/O'S TOGGLE IN THIS PROGRAM.  MAKE SURE
//    THIS WILL NOT DAMAGE YOUR HARDWARE BEFORE RUNNING THIS
//    EXAMPLE.
//
//    Monitor desired pins on an oscilloscope.
//
//    As supplied, this project is configured for "boot to SARAM" 
//    operation.  The 2833x Boot Mode table is shown below.  
//    For information on configuring the boot mode of an eZdsp, 
//    please refer to the documentation included with the eZdsp,  
//
//       $Boot_Table:
//
//         GPIO87   GPIO86     GPIO85   GPIO84
//          XA15     XA14       XA13     XA12
//           PU       PU         PU       PU
//        ==========================================
//            1        1          1        1    Jump to Flash
//            1        1          1        0    SCI-A boot
//            1        1          0        1    SPI-A boot
//            1        1          0        0    I2C-A boot
//            1        0          1        1    eCAN-A boot
//            1        0          1        0    McBSP-A boot
//            1        0          0        1    Jump to XINTF x16
//            1        0          0        0    Jump to XINTF x32
//            0        1          1        1    Jump to OTP
//            0        1          1        0    Parallel GPIO I/O boot
//            0        1          0        1    Parallel XINTF boot
//            0        1          0        0    Jump to SARAM	    <- "boot to SARAM"
//            0        0          1        1    Branch to check boot mode
//            0        0          1        0    Boot to flash, bypass ADC cal
//            0        0          0        1    Boot to SARAM, bypass ADC cal
//            0        0          0        0    Boot to SCI-A, bypass ADC cal
//                                              Boot_Table_End$
//
// DESCRIPTION:
//
//     Three different examples are included. Select the example 
//     (data, set/clear or toggle) to execute before compiling using
//     the #define statements found at the top of the code.   
//
//
//     Toggle all of the GPIO PORT pins 
//        
//    The pins can be observed using Oscilloscope.  
// 
//
//###########################################################################
// $TI Release: 2833x/2823x Header Files V1.32 $
// $Release Date: June 28, 2010 $
//###########################################################################

#include "DSP28x_Project.h"     // Device Headerfile and Examples Include File
#include "math.h"
// Select the example to compile in.  Only one example should be set as 1
// the rest should be set as 0.
#define EXAMPLE1 1  // Use DATA registers to toggle I/O's
//#define EXAMPLE2 0  // Use SET/CLEAR registers to toggle I/O's
//#define EXAMPLE3 0  // Use TOGGLE registers to toggle I/O's

float t,ton,d,d1,dr,f;//t = Switching period,dr = duty-ratio,f = frequency
// Prototype statements for functions found within this file.
void delay_loop(void); //decides the ton period of pulse
void delay_loop1(void);//decides the pulse will remain 'zero
void Gpio_select(void);
void Gpio_example1(void);
//void Gpio_example2(void);
//void Gpio_example3(void);

void main(void)
{

// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2833x_SysCtrl.c file.
   InitSysCtrl();
   
// Step 2. Initalize GPIO: 
// This example function is found in the DSP2833x_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 DSP2833x_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 DSP2833x_DefaultIsr.c.
// This function is found in DSP2833x_PieVect.c.
   InitPieVectTable();

	
// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP2833x_InitPeripherals.c
// InitPeripherals(); // Not required for this example
	
// Step 5. User specific code:
	
#if EXAMPLE1

    // This example uses DATA registers to toggle I/O's
    Gpio_example1();

#endif  // - EXAMPLE1

#if EXAMPLE2

    // This example uses SET/CLEAR registers to toggle I/O's
    Gpio_example2();
    
#endif

#if EXAMPLE3

    // This example uses TOGGLE registers to toggle I/O's
    Gpio_example3();
    
#endif

} 	
//default values
f=50;
t=1/f;
dr=1;
d=dr*t;
ton=d;
d1=t-d;


void delay_loop()
{
    volatile long i;
    for (i = 0; i < d; i++) {}
}

void delay_loop1()
{
    volatile long i;
    for (i = 0; i < d1; i++) {}
}


void Gpio_example1(void)
{ 
   // Example 1:
   // Toggle I/Os using DATA registers

   for(;;)
   {   
       GpioDataRegs.GPADAT.bit.GPIO1    = 1;
   //    GpioDataRegs.GPBDAT.all    =0x0000000A;
       
       delay_loop();

       GpioDataRegs.GPADAT.bit.GPIO1    = 0;
    //   GpioDataRegs.GPBDAT.all    =0x00000005;
    
       delay_loop1();
    }
}

//void Gpio_example2(void)
//{
   // Example 2:
   // Toggle I/Os using SET/CLEAR registers
//   for(;;)
//   {
   
 //      GpioDataRegs.GPASET.all    =0xAAAAAAAA;
//       GpioDataRegs.GPACLEAR.all  =0x55555555;
 ///
//       GpioDataRegs.GPBSET.all    =0x0000000A;
//       GpioDataRegs.GPBCLEAR.all  =0x00000005;
              
//       delay_loop();

 //      GpioDataRegs.GPACLEAR.all    =0xAAAAAAAA;
  //     GpioDataRegs.GPASET.all      =0x55555555;

  //     GpioDataRegs.GPBCLEAR.all    =0x0000000A;
  //     GpioDataRegs.GPBSET.all      =0x00000005;
 //
    //   delay_loop();
   
   // }
//}

//void Gpio_example3(void)
//{
   // Example 2:
   // Toggle I/Os using TOGGLE registers

   // Set pins to a known state
   
 //     GpioDataRegs.GPASET.all    =0xAAAAAAAA;
 //     GpioDataRegs.GPACLEAR.all  =0x55555555;
 //
 //     GpioDataRegs.GPBSET.all    =0x0000000A;
//      GpioDataRegs.GPBCLEAR.all  =0x00000005;

   // Use TOGGLE registers to flip the state of
   // the pins. 
   // Any bit set to a 1 will flip state (toggle)
   // Any bit set to a 0 will not toggle.   

  // for(;;)
//   {
 //     GpioDataRegs.GPATOGGLE.all =0xFFFFFFFF;
 //     GpioDataRegs.GPBTOGGLE.all =0x0000000F;
   //   delay_loop();
  //  }
//}



void Gpio_select(void)
{

   
    EALLOW;
	GpioCtrlRegs.GPAMUX1.bit.GPIO1 = 0;  //  GPIO
//	GpioCtrlRegs.GPAMUX2.all = 0x00000000;  // All GPIO
//	GpioCtrlRegs.GPAMUX1.all = 0x00000000;  // All GPIO
    GpioCtrlRegs.GPADIR.bit.GPIO1 = 1;   //  output
 //   GpioCtrlRegs.GPBDIR.all = 0x0000000F;   // All outputs
    EDIS;
     
}     
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// No more.
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