tms470r1a256_sci2_03.c

tmp470开发板的源程序

//*******************************************************************************
//  TMS470 Demo - SCI2 9600 GIOA To HET Byte Exchange
//
//  Description; Transmit GIODINA as a character using SCI2 TX and receive a
//  character using SCI2 RX. RX'ed character bits 0x04 and 0x08 transfered to
//  HET0 and HET2 respectively. RX interrupts is used.
//  ACLK = ICLK = SYSCLK = MCLK = 12MHz
//  Baud rate divider with 12MHz ICLKL @9600 = 12MHz/(8*9600)-1 = 0x9b
//
//  //*An external 12Mhz XTAL on OSCIN OSCOUT with proper load caps required*//	
//
//              TMS-FET470A256
//             -----------------
//         /|\|            OSCIN|-
//          | |                 | 12MHz
//          --|PLLDIS     OSCOUT|-
//            |                 |
//        --->|GPIOA      SCI2TX|------------>
//        --->|                 | 9600 - 8N1
//            |           SCI2RX|<------------
//            |             HET0|---> LED
//            |             HET2|---> LED
//
//  M.Buccini/A.Dannenberg
//  Texas Instruments, Inc
//  January 2005
//  Built with IAR Embedded Workbench Version: 4.20A
//******************************************************************************

#include <intrinsic.h>
#include "iotms470r1a256.h"
#include "tms470r1a256_bit_definitions.h"

void main(void)
{
  PCR = CLKDIV_1;                         // ICLK = SYSCLK
  PCR |= PENABLE;                         // enable peripherals

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

  SCI2CTL3 &= ~SW_NRESET;                 // Reset SCI state machine
  SCI2CCR = TIMING_MODE_ASYNC + CHAR_8;   // Async, 8-bit Char
  SCI2CTL1 |= RXENA;                      // RX enabled
  SCI2CTL2 |= TXENA;                      // TX enabled
  SCI2CTL3 |= CLOCK + RX_ACTION_ENA;      // Internal clk, RX int
  SCI2LBAUD = 0x9b;                       // 12MHz/(8*9600)-1
  SCI2PC2 |= RX_FUNC;                     // SCIRX is the SCI receive pin
  SCI2PC3 |= TX_FUNC;                     // SCITX is the SCI transmit pin
  SCI2CTL3 |= SW_NRESET;                  // Configure SCI2 state machine
  REQMASK = (1 << CIM_SCI2RX);            // Enable SCI2RX int channel
  __enable_interrupt();                   // Enable interrupts

  for (;;)
  {
    SCI2TXBUF = GIODINA;
    for (volatile int i = 0; i < 10000; i++);
  }
}
//------------------------------------------------------------------------------
// TMS470R1A256 Standard Interrupt Handler
//------------------------------------------------------------------------------
#pragma vector = IRQV
__irq __arm void irq_handler(void)
{
  switch ((0xff & IRQIVEC) - 1)
  {
    case CIM_SCI2RX :
      if (!(SCI2RXBUF & 0x4))
        HETDCLR = 0x1;
      else
        HETDSET = 0x1;

      if (!(SCI2RXBUF & 0x8))
        HETDCLR = 0x4;
      else
        HETDSET = 0x4;
      break;
  }
}