DAD

 Syntax: DAD Rhp

Where Rhp can be any Higher Order register of the pair. Pair may be BC or DE.

Byte: 1byte

Addressing Mode: Register Addressing

Working: 

1. 

2. Rlp+L= L

3. Rhp+H = H

4. Flag

Example: DAD B ..... HL= hl+ bc

where [BC] = 22 00H and [HL]= 11 11H

After execution of DAD B

[HL]= 3311H

And  [BC]=2200H

//

L=L+C

H= H+B

BC= 23 FF

HL= 11 11

HL=  3410