I Am Using 89c51 Timer Pin In Counter Mode. I Am Also Using A Sensor That Is Connected To The Port Pin Directly To Count The Pulses At The Timer Pin. Still I Am Getting Noise Spikes. I Can't Use Any Port Pin To Count The Events. Because I Need The Counts Even At The Background As Well. I have Connected Keyboard As Well. During The Keyboard Routine As Well The Pulses Are To Be Count. Hence Suggest Me Some Hardware Or Software To Eliminate The Noise Generated.