Hi all, I think this is a long mail. Please excuse me no other way to explain my problem. Please help I am having a system with two RTD checking the temperature at two different location. I am using AMUX channel 0 and 1 for connecting it to the 12 bit ADC. The reference volatage for the ADC is taken from the DAC (12 bit). I am using timer 2 overflow for the conversion start. Its time base is SYSCLK/12 (System clock is 16 MHz internal osci) I gave 0.5mS settling time. Actual requirment is 1uSec only. I have a seven segment display drive which rquires a interrupt free routine to update the display. So when i require to update it I disabled the interrupt through global disable. When I go through the display routine the temperature routine fluctuates. My doubt's are 1. Will the timer will run even when the EA is cleared to '0'? Then the ADC routine will have a value 0000 in ADC0 (Am I right?) 2. When I increased the display update speed (I mean the delay between the data bits inside the routine )the fluctuation reduced but how? 3. If interrupt is disabled whether the counter resets to zero and restarts when it is again enabled? 3. If the display routine is commented there is no fluctuation in the temperature. My processor 8051f020 compiler - c51 rgds Deepak