dc_pwm.c

开发环境为CCS。DSP12个典型例子源码

// TI File $Revision: /main/3 $
// Checkin $Date: July 2, 2007   11:32:39 $
//###########################################################################
//
// FILE:   DC_PWM.c
//
// TITLE:  DSP2812 Event Manager PWM Generation.
//
  

//###########################################################################
// $TI Release: DSP281x Header Files V1.11 $
// $Release Date: September 26, 2007 $
//###########################################################################

#include "DSP281x_Device.h"     // DSP281x Headerfile Include File
#include "DSP281x_Examples.h"   // DSP281x Examples Include File


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

// Global counts used in this example


void main(void)
{

// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP281x_SysCtrl.c file.
   InitSysCtrl();

// Step 2. Initalize GPIO: 
// This example function is found in the DSP281x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio();  // Skipped for this example  

// Initialize only GPAMUX and GPBMUX for this test
   EALLOW;
   // Enable PWM pins
   GpioMuxRegs.GPAMUX.all = 0x00FF; // EVA PWM 1-2  pins
	 
   EDIS;
    
// 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 DSP281x_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 DSP281x_DefaultIsr.c.
// This function is found in DSP281x_PieVect.c.
   InitPieVectTable();
   
// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP281x_InitPeripherals.c
// InitPeripherals(); // Not required for this example
   init_eva();

// Step 5. User specific code, enable interrupts:


  // Just sit and loop forever:
  // PWM pins can be observed with a scope.	
  for(;;);

}

void init_eva()
{

   // Initalize EVA Timer1 
   EvaRegs.T1PR = 0xFFFF;       // Timer1 period
   EvaRegs.T1CMPR = 0x3C00;     // Timer1 compare
   EvaRegs.T1CNT = 0x0000;      // Timer1 counter
   EvaRegs.T1CON.all = 0x1042;   


  // Drive T1/T2 PWM by compare logic
  EvaRegs.GPTCONA.bit.TCMPOE = 1;
  // Polarity of GP Timer 1 Compare = Active low
  EvaRegs.GPTCONA.bit.T1PIN = 1;
  // Enable compare for PWM1-PWM2
  EvaRegs.CMPR1 = 0x0C00;

  EvaRegs.ACTRA.all = 0x0666;
  EvaRegs.DBTCONA.all = 0x0000; // Disable deadband
  EvaRegs.COMCONA.all = 0xA600;


} 



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