8051 initial logic for interrupt

Discussion in 'Embedded Systems and Microcontrollers' started by dhanasingaraja, Apr 2, 2012.

  1. dhanasingaraja

    Thread Starter New Member

    Nov 25, 2011
    Hello greats,

    I use external interrupt in my project.initially if the interrupt signal is low (from spdt switch sw5) when switching on the controller,controller runs very slowly in proteus simulation and real time also.can anybody tell the reason for that? this is my circuit.
  2. jimkeith

    Well-Known Member

    Oct 26, 2011
    you must set the interrupt to be edge-triggered, otherwise it continues to re-execute upon return from interrupt--setb it0 (or it1) in the tcon register