fet140_svs01.c

来自「msp430f14x 系列片内外设的实例代码」· C语言 代码 · 共 42 行

//*******************************************************************************
//  MSP-FET430P140 Demo - SVS POR @ 2.5V VCC
//
//  Description; The SVS POR feature is used to disable normal operation that 
//  toggles P1.0 by xor'ing P1.0 inside of a software loop.
//  In the example, when VCC is above 2.5V, the MSP430 toggles P1.0. When VCC is
//  below 2.5V, the SVS resets the MSP430, and no toggle is seen.
//  ACLK= n/a, MCLK= SMCLK= default DCO ~ 800k
//  //*MSP430F169 Device Required*//
//
//                MSP430F169
//             -----------------
//         /|\|              XIN|-  
//          | |                 |
//          --|RST          XOUT|-
//            |                 |
//            |             P1.0|-->LED
//
//  M. Buccini
//  Texas Instruments, Inc
//  March 2004
//  Updated for IAR Embedded Workbench Version: 2.21B
//******************************************************************************

#include  <msp430x16x.h>

void main(void)
{ 
  WDTCTL = WDTPW + WDTHOLD;             // Stop watchdog timer
  P1DIR |= 0x01;                        // Set P1.0 to output direction
  SVSCTL = 0x60 + PORON;                // SVS POR enabled @ 2.5V  

  for (;;)                              
  {
    volatile unsigned int i;
    i = 50000;                          // Delay
    do (i--);
    while (i != 0);
    P1OUT ^= 0x01;                      // Toggle P1.0 using exclusive-OR
  }
}