Use watch-dog timer

This example illustrates how the watch-dog timer should not be used. A command used to reset this timer is intentionally left out in the main program loop, thus enabling it to win the time battle and cause the microcontroller to be reset. As a result, the microcontroller will be reset every time, which is indicated by PORTB LEDs blinking.

'Header******************************************************
program example_5 ' Program name
main: ' Start of program
OPTION_REG = 0x0E ' Prescaler is assigned to timer WDT (1:64)
asm CLRWDT ' Assembly command to reset WDT timer
end asm
PORTB = 0x0F ' Initial value of the PORTB register
TRISB = 0 ' All PORTB pins are configured as outputs
Delay_ms(300) ' 30mS delay
PORTB = 0xF0 ' Port PORTB value different from initial
while 1 ' Endless loop. Program remains here until WDT
wend ' timer resets the microcontroller
end. ' End of program

In order to make this example work properly, it is necessary to enable the watchdog timer by selecting the Watchdog Timer - Enabledoption in mE programmer.