UGC NET CSE | June 2016 | Part 3 | Question: 3

Question

Which of the  following in 8085 microprocessor  performs HL=HL+DE ?

• A. DAD D
• B. DAD H
• C. DAD  B
• D. DAD SP

Answer 1

Answer: (A)

Explanation: DAD will perform Double addition (16 bit) between HL pair and any other pair of register. Among HL, BC, DE and SP; B, H and D register will be used first.
So, DAD H will do HL = HL + HL;
DAD B will do HL = HL + BC;
DAD D will do HL = HL + DE;
SP is stack pointer and it is not a pair register, DAD SP will do HL = HL + SP;
So, option (A) is correct.

Answer 2

Ans: A

ref: https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjG9pLEiZ_WAhUEPY8KHamSCP4QFgglMAA&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FIntel_8085&usg=AFQjCNGEOASy59dpF1mnBsZaO3gFc3Mnxg