main.c

富士通mb90425系列:f2mc-16lx的看门狗例程。

#include "mb90425.h"

/*---------------------------------------------------------------------------
  #Defines
/*---------------------------------------------------------------------------*/


/*---------------------------------------------------------------------------
  Globals
/*---------------------------------------------------------------------------*/


/*---------------------------------------------------------------------------
  Functions
/*---------------------------------------------------------------------------*/

/* Note:
   The -A and -B versions include a CPU Detection Reset Circuit. 
   This must be cleared periodically to prevent program reset.

   The conditions for clearing the counter of this circuit are given below:
   1. Writing 0 to CL bit of LVRC register
   2. Internal reset
   3. Stopping main oscillation clock
   4. Transition to sleep mode
   5. Transition to time-base timer mode or timer mode
   6. Starting hold
*/

void clear_CPU_operation_detection (void)
{
 LVRC = 0x35;	        /* clears CPU operation detection */
}

/*---------------------------------------------------------------------------
  Functions: Real-Time Watch-Timer
/*---------------------------------------------------------------------------*/

void Init_RealTimeWatchTimer(unsigned char hours,
                             unsigned char minutes,
                             unsigned char seconds)
{
  WTCRL = 0x00;      /* stop Real-Time Watch-Timer */

  WTBRH = 0x1E;      /* Set Prescaler to 0x1E847F ...                      */
  WTBRM = 0x84;      /* ... that means 1 second @ 4Mhz                     */
  WTBRL = 0x7F;      /* Note: Prescaler is based on the half crystal clock */


  WTSR = seconds;    /* Preset seconds */
  WTMR = minutes;    /* Preset minutes */
  WTHR = hours;      /* Preset hours   */
  
  WTCRH = 0x02;      /* enable Interrupts for sub-seconds-overflow */
  
  WTCRL = 0x05;      /* start Real-Time Watch-Timer */
}

/*---------------------------------------------------------------------------
  Interrupts
/*---------------------------------------------------------------------------*/
__interrupt void irq_RealTimeWatch (void)
{
  PDR4 = ~(WTSR & 0x3f); /* put seconds-register tor Port 4 (LED-Port of FlashCan100P */
  WTCRH = 0x02;          /* clear Interrupt Flag */   
}


/*---------------------------------------------------------------------------
  MAIN.C
/*---------------------------------------------------------------------------*/

void main(void)
{
  InitIrqLevels();
  __set_il(7);            /* allow all levels */
  __EI();                 /* globaly enable interrupts */

  PDR4 = 0xFF;            /* switch off all leds */
  DDR4 = 0xFF;            /* set parallel port direction register : output */

  Init_RealTimeWatchTimer(0,0,6); /* Initialize Real-Time Watch-Counter */

  while(1)
    clear_CPU_operation_detection();

}