DAA and DAD

Question

Specify the operations which can be performed along with the following given instructions?

a) DAA

b) DAD

Answer 1

a) DAA instruction is used within the program after the ADD or ADC instruction. After the execution of ADD or ADC instruction, result comes out to be in hexadecimal and it is kept in the accumulator. DAA instruction operates upon this result and gives the final result in decimal system.

b) At the execution of DAD B instruction, matter of the B-C register pair is appended to the matter of the H-L pair and the sum is kept in the H-L pair.