I m using AT89c2051 and using DS1232 to reset the microcontrolller in failed condition. Microcontroller has to give some pulsed signal to DS1232. In any fault condition if microcontroller is nt working, then it will not give the pulsed signal to DS1232, then DS1232 will reset the microcontroller. But here in my circuit if ground pin is open still microcontroller is giving singal to DS1232. and remaining pins are going high....
actually for testing i broke the GND leg of the microcontroller.... and i m giving ground to GND pin externally by wire while switching it ON. aftr that i m removing the ground wire from the GND leg of microcontroller, but still the program is wrking...
You must have a pin that is active low and that is making a ground path to power the chip. You must make the break between the power supply and the circuit of the micro. Why not read a push button and go into an infinite loop when it's pushed?