main.c

介绍了飞思卡尔单片机的基本应用 整个编程流程

#include <hidef.h>      /* common defines and macros */
#include <mc9s12dg128.h>     /* derivative information */
#pragma LINK_INFO DERIVATIVE "mc9s12dg128b"

int counter;
int flag;
void TimerOverflow(void) {
/* This function waits for th timer overflow.
Then it changes the LEDs bargraph display */
  while (TCNT != 0x0000);
  while (TCNT == 0x0000);
  if(flag)
  counter--;
  else
  counter++;
  
  if (counter == 8) PORTB = 0x7f; /* LEDs' lightshow */
  if (counter == 7) PORTB = 0xbf;
  if (counter == 6) PORTB = 0xdf;
  if (counter == 5) PORTB = 0xef;
  if (counter == 4) PORTB = 0xf7;
  if (counter == 3) PORTB = 0xfb;
  if (counter == 2) PORTB = 0xfd;
  if (counter == 1) PORTB = 0xfe;
}

void main(void)
{
  TSCR1 = 0x80; /* enable timer TCNT */
  TSCR2 = 0x03; /* TCNT prescaler setup */
  counter = 0;
   
  DDRB=0xff; /* PTB as output */
  PORTB=0xff;  /* LEDs off */
  asm{
  nop
  } 
  for (;;)
  { 
    TimerOverflow();
    if (counter == 8) {
         flag=1;
        /* counter = 0;*/
         TSCR2 = 0x03;  /* TCNT prescaler switch */ 
    }
    if(counter==1) {
    flag=0;
    TSCR2= 0x05;
    }
  }
}

/* please make sure that you never leave this function */