f_8_11_reset.c

PIC_Hi-Tech_C_Mike_Pearces_I2C_routines Microchi PIC_Hi-Tech C_I2C_for_EEPROM_24LC01B Code

#include "config.h"

#include "serial.c"


// tests power-on reset bits, watchdog timer, and persistent variables 
char getch (void);
void putch (char c);

// return 8 bit char from Recieve port 
char getch (void)
{
  unsigned char c;

  while (!RCIF);  // check RCIF bit 
  c = RCREG;
  return(c);
}

// send 8 bit char to Recieve port 
void putch (char c)
{
  // wait until transmit reg empty 
  while (!TXIF); // check TXIF bit 
  TXREG = c;
}

     
void pcrlf (void)
{
  putch(0x0a);
  putch(0x0d);
}

// 'persisent' prevents reset_cnt from being cleared on reset
// however, reset_cnt is still stored in register bank, so is volatile
// For persistent variables, CANNOT assume any initial values!

#if defined(HI_TECH_C)
persistent char reset_cnt;
#endif

#if defined(__18CXX)
//MCC18 initialization controlled by startup code that is linked
// in - either init all memory zero, just do explicit initializations,
// or do no initialization at all. This project uses
// the startup code that only does explicit initialization, so
// the variable below is not initialized, cannot assume an initial value
char reset_cnt;  
#endif

void main(void)
{

  int i;
  char c;

  serial_init(95,1); // 19200 in HSPLL mode, crystal = 7.3728 MHz 
  pcrlf(); // this subroutine prints a newline to the terminal
  if (POR == 0){  // bit 2 in RCON register, cleared to 0 on power-up reset
    printf("Power-on reset has occurred.");
    pcrlf();
    POR = 1;  // setting to bit to 1 means that will remain a '1' for other reset types
    reset_cnt = 0;
  }
  if (TO == 0) {
    SWDTEN = 0; // disable watchdog timer
    printf("Watchdog timer reset has occurred.\n");
    pcrlf();
  }
  i = reset_cnt;
  printf("Reset cnt is: %d",i);
  pcrlf();
  reset_cnt++;
  while(1) {
    printf("'1' to enable watchdog timer"); pcrlf();
    printf("'2' for sleep mode");  pcrlf();
    printf("'3' for both watchdog timer and sleep mode");  pcrlf();
    printf("Anything else does nothing, enter keypress: ");
    c = getch();
    putch(c);
    pcrlf();
    if (c == '1') SWDTEN = 1;  // enable watchdog timer
    else if (c == '2') {
	// use SLEEP() instead of asm("sleep") for portability
	// between HI-TECH and MCC Compilers
      	SLEEP(); 
    }
    else if (c == '3') {
      SWDTEN = 1;     // enable watchdog timer
      SLEEP(); 
    }
  }
}