So, that is though this apart we have already discussed how to access this external ROM, ALE signal is activated the address is given lower order address given the higher order address is put on the PC high and this PSEN bar line is given when PSEN bar is going high the data the Opcode MOVX Opcode is available on to the data bus then the decoder will decode that MOVX instruction and now it will go in to the second stage second stage and in that second stage it has to it puts the read bar line.
त्यामुळेच पीएसईएन बार अधिक वाढत आहे, डेटा बसवर एमओव्हीएक्स ऑपकोड उपलब्ध आहे नंतर डीकोडर त्या एमओव्हीएक्सच्या सूचनांना डीकोड करेल आणि आता ती दुसर्या टप्प्यात जाईल. त्या दुसर् या चरणात त्यास रिड बारची लाइन घ्यावी लागेल.