tms470r1a256_sci1_01.c

tmp470开发板的源程序

//*******************************************************************************
//  TMS470 Demo - SCI1 19200 Echo With Interrupt
//
//  Description; Echo back received character in an endless loop. SCI2 RX
//  interrupt used. RX interrupt used.
//  ACLK = ICLK = SYSCLK = MCLK  = 12MHz
//  Baud rate divider with 12MHz ICLKL @19200 = 12MHz/(8*19200)-1 = 0x4D
//
//  //*An external 12Mhz XTAL on OSCIN OSCOUT with proper load caps required*//	
//
//              TMS-FET470A256
//             -----------------
//         /|\|            OSCIN|-
//          | |                 | 12MHz
//          --|PLLDIS     OSCOUT|-
//            |                 |
//            |           SCI1TX|------------>
//            |                 | 19200 - 8N1
//            |           SCI1RX|<------------
//
//  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

  SCI1CTL3 &= ~SW_NRESET;                 // Reset SCI state machine
  SCI1CCR = TIMING_MODE_ASYNC + CHAR_8;   // Async, 8-bit Char
  SCI1CTL1 |= RXENA;                      // RX enabled
  SCI1CTL2 |= TXENA;                      // TX enabled
  SCI1CTL3 |= CLOCK + RX_ACTION_ENA;      // Internal clock. RX interrrupt
  SCI1LBAUD = 0x4d;                       // 12MHz/(8*19200)-1
  SCI1PC2 |= RX_FUNC;                     // SCIRX is the SCI receive pin
  SCI1PC3 |= TX_FUNC;                     // SCITX is the SCI transmit pin
  SCI1CTL3 |= SW_NRESET;                  // Configure SCI1 state machine
  REQMASK = (1 << CIM_SCI1RX);            // Enable SCI1RX channel
  __enable_interrupt();                   // Enable interrupts

  for (;;){}                              // Wait in enless loop
}
//------------------------------------------------------------------------------
// TMS470R1A256 Standard Interrupt Handler
//------------------------------------------------------------------------------
#pragma vector = IRQV
__irq __arm void irq_handler(void)
{
  switch ((0xff & IRQIVEC) - 1)
  {
    case CIM_SCI1RX : SCI1TXBUF = SCI1RXBUF; break;
  }
}