tms470r1b1m_rti_01.c

TMS-FET470B1M C Examples

//*******************************************************************************
//  TMS470 Demo - RTI Interrupts From TAP, CMP1 and CMP2
//
//  Description; Service TAP, CMP1 and CMP2 interrupts and toggle Pin HET0,
//  HET12 and HET31 in response. Software adds offset to CMP1 and CMP2 to
//  maintain intervals.
//
//  SYSCLK = MCLK = ACLK = 8 x 7.3728MHz = 58.9824MHz
//  ICLK = SYSCLK / 2 = 29.4912MHz
//
//  //*An external 7.3728MHz XTAL with proper load caps is required*//	
//
//              TMS-FET470B1M
//             -----------------
//            |            OSCIN|-
//            |                 | 7.3728MHz
//         +--|PLLDIS     OSCOUT|-
//         |  |                 |
//        -+- |             HET0|---> LED Toggle
//            |             HET1|---> LED Toggle 2X
//            |             HET2|---> LED Toggle 4X
//            |                 |
//
//  A.Dannenberg / J.Mangino
//  Texas Instruments, Inc
//  July 29th 2005
//  Built with IAR Embedded Workbench Version: 4.20A
//******************************************************************************

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

void main(void)
{
  PCR = CLKDIV_2;                         // ICLK = SYSCLK / 2
  GCR = ZPLL_CLK_DIV_PRE_1;               // SYSCLK = 8 x fOSC
  PCR |= PENABLE;                         // Enable peripherals

  HETDIR  = 0xFFFFFFFF;                   // HETx Output direction
  HETDOUT = 0xFFFFFFFF;

  RTIPCTL = 4;                            // Preload modulo counter
  RTICNTL |= TAPENA;                      // Enable TAP interrupt
  RTICMP1 = 1048576;
  RTICMP2 = 524288;
  RTICINT |= CMP1ENA + CMP2ENA;           // Enable CMP1/CMP2 interrupts
  REQMASK = (1 << CIM_TAP)+(1 << CIM_COMP1)+(1 << CIM_COMP2);
                                          // Enable RTI TAP/CMP1/2 chan's
  __enable_interrupt();                   // Enable interrupts

  for (;;) {}
}
//------------------------------------------------------------------------------
// TMS470R1B1M Standard Interrupt Handler
//------------------------------------------------------------------------------
__irq __arm void irq_handler(void)
{
  switch ((0xff & IRQIVEC) - 1)
  {
    case CIM_TAP:
      RTICNTL &= ~0x80;                   // Clear TAP flag
      HETDOUT ^= 0x01;                    // Toggle using exclusive-OR
      break;
    case CIM_COMP1:
      RTICMP1 += 1048576;                 // Add offset
      RTICINT &= ~0x80;                   // Clear CMP1 flag
      HETDOUT ^= 0x02;                    // Toggle using exclusive-OR
      break;
    case CIM_COMP2:
      RTICMP2 += 524288;                  // Add offset
      RTICINT &= ~0x40;                   // Clear CMP2 flag
      HETDOUT ^= 0x04;                    // Toggle using exclusive-OR
      break;
  }
}