trap_test.c - Code which causes a math error (divide by zero) trap

Perform a divide by 0. Because there is no handler defined for the math error trap, the _DefaultInterrupt will catch it and report an error. Code in trap_test_handled.c gives an example of an ISR that handles this trap.

 
#include "pic24_all.h"

int main(void) {

If u8_zero is not declared as volatile, then the compiler will optimize out the 1/u8_zero code, NOT producing a divide by zero!

  volatile uint8_t u8_zero;

  configBasic(HELLO_MSG);
  /** start **/
  while (1) {
    outString("Hit a key to start divide by zero test...");
    inChar();
    outString("OK. Now dividing by zero.\n"
              "The math errror trap is not handled, so\n"
              "the _DefaultInterrupt handler should be\n"
              "called, causing the chip to reset.\n\n");
    u8_zero = 0;
    u8_zero = 1/u8_zero;
    doHeartbeat();
  }
}