// TI File $Revision: /main/7 $
// Checkin $Date: August 10, 2007   09:04:57 $
//###########################################################################
//
// FILE:    Example_2833xEPwmUpDownAQ.c
//
// TITLE:   Action Qualifier Module - Using up/down count
//
// ASSUMPTIONS:
//
//    This program requires the DSP2833x header files.  
//
//    Monitor ePWM1-ePWM3 pins on an oscilloscope as described
//    below.
//
//       EPWM1A is on GPIO0
//       EPWM1B is on GPIO1
//
//       EPWM2A is on GPIO2
//       EPWM2B is on GPIO3
//
//       EPWM3A is on GPIO4
//       EPWM3B is on GPIO5
//
//    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:
//
//    This example configures ePWM1, ePWM2, ePWM3 to produce an
//    waveform with independant modulation on EPWMxA and
//    EPWMxB.
//
//    The compare values CMPA and CMPB are modified within the ePWM's ISR
//
//    The TB counter is in up/down count mode for this example. 
//
//    View the EPWM1A/B, EPWM2A/B and EPWM3A/B waveforms 
//    via an oscilloscope
//
//
//###########################################################################
// $TI Release: DSP2833x Header Files V1.03 $
// $Release Date: December 3, 2007 $
//###########################################################################


#include "DSP2833x_Device.h"     // DSP2833x Headerfile Include File
#include "DSP2833x_Examples.h"   // DSP2833x Examples Include File

typedef struct
{
   volatile struct EPWM_REGS *EPwmRegHandle;
   Uint16 EPwm_CMPA_Direction;
   Uint16 EPwm_CMPB_Direction;
   Uint16 EPwmTimerIntCount;
   Uint16 EPwmMaxCMPA;
   Uint16 EPwmMinCMPA;
   Uint16 EPwmMaxCMPB;
   Uint16 EPwmMinCMPB;   
}EPWM_INFO;


// Prototype statements for functions found within this file.
void InitEPwm1Example(void);
void InitEPwm2Example(void);
void InitEPwm3Example(void);
interrupt void epwm1_isr(void);
interrupt void epwm2_isr(void);
interrupt void epwm3_isr(void);
void update_compare(EPWM_INFO*);

// Global variables used in this example
EPWM_INFO epwm1_info;
EPWM_INFO epwm2_info;
EPWM_INFO epwm3_info;

// Configure the period for each timer
#define EPWM1_TIMER_TBPRD  2000  // Period register
#define EPWM1_MAX_CMPA     1950
#define EPWM1_MIN_CMPA       50
#define EPWM1_MAX_CMPB     1950
#define EPWM1_MIN_CMPB       50

#define EPWM2_TIMER_TBPRD  2000  // Period register
#define EPWM2_MAX_CMPA     1950      
#define EPWM2_MIN_CMPA       50      
#define EPWM2_MAX_CMPB     1950      
#define EPWM2_MIN_CMPB       50      

#define EPWM3_TIMER_TBPRD  2000  // Period register
#define EPWM3_MAX_CMPA      950  
#define EPWM3_MIN_CMPA       50  
#define EPWM3_MAX_CMPB     1950  
#define EPWM3_MIN_CMPB     1050  

// To keep track of which way the compare value is moving
#define EPWM_CMP_UP   1
#define EPWM_CMP_DOWN 0

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 case just init GPIO pins for ePWM1, ePWM2, ePWM3
// These functions are in the DSP2833x_EPwm.c file
   InitEPwm1Gpio();
   InitEPwm2Gpio();
   InitEPwm3Gpio();   
   
// 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_isr;
   PieVectTable.EPWM2_INT = &epwm2_isr;
   PieVectTable.EPWM3_INT = &epwm3_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();    
   InitEPwm2Example();
   InitEPwm3Example();
   
   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;
   PieCtrlRegs.PIEIER3.bit.INTx2 = 1;
   PieCtrlRegs.PIEIER3.bit.INTx3 = 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");
   }

} 


interrupt void epwm1_isr(void)
{
   // Update the CMPA and CMPB values
   update_compare(&epwm1_info);
   
   // Clear INT flag for this timer
   EPwm1Regs.ETCLR.bit.INT = 1;
   
   // Acknowledge this interrupt to receive more interrupts from group 3
   PieCtrlRegs.PIEACK.all = PIEACK_GROUP3;
}


interrupt void epwm2_isr(void)
{

   // Update the CMPA and CMPB values
   update_compare(&epwm2_info);

   // Clear INT flag for this timer
   EPwm2Regs.ETCLR.bit.INT = 1;
   
   // Acknowledge this interrupt to receive more interrupts from group 3
   PieCtrlRegs.PIEACK.all = PIEACK_GROUP3;
}

interrupt void epwm3_isr(void)
{

   // Update the CMPA and CMPB values
   update_compare(&epwm3_info);

   // Clear INT flag for this timer
   EPwm3Regs.ETCLR.bit.INT = 1;
   
   // Acknowledge this interrupt to receive more interrupts from group 3