tms470r1b1m_sci1_02.c

TMS-FET470B1M C Examples

//*******************************************************************************
//  TMS470 Demo - SCI1 19200 Transmit String
//
//  Description; Transmit the string "Hello World" using SCI1. The RTI tap
//  interrupt enables the SCI1 TX interrupt allowing transmission of string.
//  At completion of string transmission, the SCI1 ISR disables further
//  transmission.
//  RTI tap divides ICLK/2^20
//
//  SYSCLK = MCLK = ACLK = 8 x 7.3728MHz = 58.9824MHz
//  ICLK = SYSCLK / 2 = 29.4912MHz
//
//  Baud rate divider with 29.4912MHz ICLK @19200 =
//  29.4912MHz/(8*19200)-1 = 0xbf
//
//  //*An external 7.3728MHz XTAL with proper load caps is required*//	
//
//              TMS-FET470B1M
//             -----------------
//            |            OSCIN|-
//            |                 | 7.3728MHz
//         +--|PLLDIS     OSCOUT|-
//         |  |                 |
//        -+- |           SCI1TX|------------>
//            |                 | 19200 - 8N1
//            |           SCI1RX|<------------
//
//  A.Dannenberg / J.Mangino
//  Texas Instruments, Inc
//  July 29th 2005
//  Built with IAR Embedded Workbench Version: 4.30A
//******************************************************************************

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

const char string1[] = { "Hello World\r\n" };
unsigned int i = 0;

void main(void)
{
  PCR = CLKDIV_2;                         // ICLK = SYSCLK / 2
  GCR = ZPLL_CLK_DIV_PRE_1;               // SYSCLK = 8 x fOSC
  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;                      // Internal clock
  SCI1LBAUD = 0xbf;                       // 29.4912MHz/(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
  RTIPCTL = 4;                            // Preload modulo counter
  RTICNTL |= TAPENA;                      // Enable TAP interrupt
  REQMASK = (1 << CIM_SCI1TX)+(1 << CIM_TAP); // Enable SCI1TX, RTI tap chan's
  __enable_interrupt();                   // Enable interrupts

  for (;;) {}
}
//------------------------------------------------------------------------------
// TMS470R1B1M Standard Interrupt Handler
//------------------------------------------------------------------------------
#pragma vector = IRQV
__irq __arm void irq_handler(void)
{
  switch ((0xff & IRQIVEC) - 1)
  {
    case CIM_TAP:
      i = 0;
      SCI1TXBUF = string1[i++];           // First char to TX buffer
      SCI1CTL3 |= TX_ACTION_ENA;          // Enable TX interrupt
      RTICNTL &= ~TAPFLAG;                // Clear TAP flag
      break;
    case CIM_SCI1TX:
      if (i < sizeof string1-1)
        SCI1TXBUF = string1[i++];
      else
        SCI1CTL3 &= ~TX_ACTION_ENA;       // Disable TX interrupt
      break;
  }
}