[资料分享] DSPF28335关于SPWM的源代码

/*
* main.c
*/

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

// Prototype statements for functions found within this file.
void InitEPwm1Example(void);
extern void InitSpwm(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. Initialize 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 case just init GPIO pins for ePWM1, ePWM2, ePWM3
// These functions are in the DSP2833x_EPwm.c file
   InitEPwm1Gpio();

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

// Initialize the 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();

// Interrupts that are used in this example are re-mapped to
// ISR functions found within this file.
// EALLOW;  // This is needed to write to EALLOW protected registers
// PieVectTable.EPWM1_INT = &EPWM1_INT_ISR;

// EDIS;    // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP2833x_InitPeripherals.c
// InitPeripherals();  // Not required for this example

// For this example, only initialize the ePWM

   EALLOW;
   SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 0;
   EDIS;

   InitEPwm1Example();
   InitSpwm();

   EALLOW;
   SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1;
   EDIS;

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

// Enable CPU INT3 which is connected to EPWM1-3 INT:
   IER |= M_INT3;

// Enable EPWM INTn in the PIE: Group 3 interrupt 1-3
   PieCtrlRegs.PIEIER3.bit.INTx1 = 1;

// Enable global Interrupts and higher priority real-time debug events:
   EINT;   // Enable Global interrupt INTM
   ERTM;   // Enable Global realtime interrupt DBGM

// Step 6. IDLE loop. Just sit and loop forever (optional):
   for(;;)
   {
           __asm("          NOP");
   }

}
void InitEPwm1Example()
{
   // Setup TBCLK
   EPwm1Regs.TBPRD = 0xffff;           // Set timer period 801 TBCLKs
   EPwm1Regs.TBPHS.half.TBPHS = 0x0000;           // Phase is 0
   EPwm1Regs.TBCTR = 0x0000;                      // Clear counter

   // Set Compare values
   EPwm1Regs.CMPA.half.CMPA = 0x7fff;     // Set compare A value
   EPwm1Regs.CMPB = 0x7fff;               // Set Compare B value

   // Setup counter mode
   EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN; // Count up
   EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;        // Disable phase loading
   EPwm1Regs.TBCTL.bit.HSPCLKDIV = TB_DIV2;       // Clock ratio to SYSCLKOUT
   EPwm1Regs.TBCTL.bit.CLKDIV = TB_DIV8;

   // Setup shadowing
   EPwm1Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
   EPwm1Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
   EPwm1Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO;  // Load on Zero
   EPwm1Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO;

   // Set actions
   EPwm1Regs.AQCTLA.bit.CAU = AQ_SET;             // Set PWM1A on event A, up count
   EPwm1Regs.AQCTLA.bit.CAD = AQ_CLEAR;           // Clear PWM1A on event A, down count

   EPwm1Regs.AQCTLB.bit.CBU = AQ_SET;             // Set PWM1B on event B, up count
   EPwm1Regs.AQCTLB.bit.CBD = AQ_CLEAR;           // Clear PWM1B on event B, down count

   // Interrupt where we will change the Compare Values
   EPwm1Regs.ETSEL.bit.INTSEL = ET_CTRU_CMPA;      // Select INT on Zero event
   EPwm1Regs.ETSEL.bit.INTEN = 1;                 // Enable INT
   EPwm1Regs.ETPS.bit.INTPRD = ET_1ST;            // Generate INT on 3rd event

}