tms470r1b1m_het_pwm_02.c

TMS-FET470B1M C Examples

//******************************************************************************
//  TMS470 Demo - HET used to generate and synchronously update PWM
//
//  Program name : tms470r1b1m_HET_PWM_02.c, associated with
//                 HET program tms470r1b1m_HET_PWM_02_H.het and cstartup.s79
//
//  This programs initializes the HET using the ECMP instruction to
//  generate a PWMs and synchronously modify the duty cycle of the PWM.
//  The pulses is generated by the HET on HET0 (CC0)  lighting the
//  corresponding LEDs.
//
//  SYSCLK = MCLK = ACLK = 8 x 7.3728MHz = 58.9824MHz
//  ICLK = SYSCLK / 4 = 14.7456MHz
//
//  //*An external 7.3728MHz XTAL with proper load caps is required*//	
//
//              TMS-FET470B1M
//             -----------------
//            |            OSCIN|-
//            |                 | 7.3728MHz
//         +--|PLLDIS     OSCOUT|-
//         |  |                 |
//        -+- |             HET0|---> LED
//            |                 |
//
//  J.Mangino
//  Texas Instruments, Inc
//  October 29th 2005
//  Built with IAR Embedded Workbench Version: 4.30A
//******************************************************************************

#include <intrinsic.h>
#include "iotms470r1b1m.h"
#include "tms470r1b1m_bit_definitions.h"
#include "std_het.h"
#include "tms470r1b1m_HET_PWM_02_H.h"

__no_init volatile HETPROGRAM0_UN e_HETPROGRAM0_UN @ 0x00800000;

void MemCopy32(unsigned long *dst, unsigned long *src, int bytes)
{
  for (int i = 0; i < (bytes + 3) / 4; i++)
    *dst++ = *src++;
}

int data_het_buff [] = {0x10A5,0x0c7b,0x0852,0x0429,0xffff};
   int* ip;
void main(void)
{
  ip=data_het_buff;
  PCR = CLKDIV_2;                         // ICLK = SYSCLK / 2
  GCR = ZPLL_CLK_DIV_PRE_4;               // SYSCLK = 8 x fOSC
  PCR |= PENABLE;                         // Enable peripherals
  REQMASK =  (1 << CIM_HET1);             // Enable GIOB and HET1 ints
  HETGCR = CLK_MASTER + IGNORE_SUSPEND;   // HET Master Mode, Ignore SW BP

  // Copy HET instructions to HET RAM
  MemCopy32((void *)&e_HETPROGRAM0_UN, (void *)HET_INIT0_PST,
            sizeof(HET_INIT0_PST));

  HETPFR = 0x0000052b;                    // Set PFR register	
  HETPRY = 0x04;                          // Instruction 0 interrupt
                                          // is high priority
  HETDCLR = 0xffffffff;                   // Clear HET output latches
  HETDIR  = 0xffffffff;                    // Set HET as GIO outputs

  HETGCR |= ON;                           // Start HET

  __enable_interrupt();                   // Enable Interrupts

  while (1);                              // Loop forever...
}

//------------------------------------------------------------------------------
// This ISR is called from the HET and is used to feed
// the HET PWM output by directly writing to the data field of the MOV32
// instruction on every 3rd ISR entry. This functionality could be moved
// into the HET program for CPU load reduction.
//------------------------------------------------------------------------------
void HET1_Instr0_handler()
{
  static unsigned int Ctr = 0;

  if (++Ctr == 4) Ctr = 0;                      // Count 0, 1, 2, 0, 1, ...

  if (Ctr) return;                              // Update sample data every
                                                // 3rd ISR entry only
 if (*ip != 0xffff)
  {
  HET_L04_0.memory.data_word = ((0x01ffff10) &(*ip++<<5));
  }
 else
 {
  ip = data_het_buff;
  HET_L04_0.memory.data_word = ((0x01ffff10) &(*ip++<<5));
  }
}
//------------------------------------------------------------------------------
// HET Interrupt Level 1 Handler
//------------------------------------------------------------------------------
void HET1_irq_handler()
{
  switch ((HETOFF1 & 0xff) - 1)
  {
    case 2 :                                    // Int on instruction 0
      HET1_Instr0_handler();
      break;
  }
}
//------------------------------------------------------------------------------
// TMS470R1B1M Standard Interrupt Handler
//------------------------------------------------------------------------------
__irq __arm void irq_handler(void)
{
  switch ((IRQIVEC & 0xff) - 1)
  {
    case CIM_HET1 :
      HET1_irq_handler();
      break;
  }
}