Hello everyone. I have proteus7.4 serverpack version(it supports even ARM7TDMI) which is interlinked with keil s/w. I am able to perform simulation with 8051 but when it comes with ARM7 its not. boz ARM7 requires 3.3v and 1.1v supply for its GPIO's, where proteus provides min 5v supply. So plz help me how to overcome this problem.