8085 program to swap two 8 bit numbers using Direct addressing mode
Problem – Write a program to swap two 8-bit numbers using direct addressing mode where starting address is 2000 and the first 8-bit number is stored at 3000 and the second 8-bit number is stored at 3001 memory address.
Attention reader! Don’t stop learning now. Get hold of all the important CS Theory concepts for SDE interviews with the CS Theory Course at a student-friendly price and become industry ready.
- Load a 8-bit number from memory 3000 into accumulator
- Move value of accumulator into register H
- Load a 8-bit number from memory 3001 into accumulator
- Move value of accumulator into register D
- Exchange both the register pairs
|2000||LDA||||[A] <- |
|2003||MOV||H, A||[H] <- [A]|
|2004||LDA||||[A] <- |
|2007||MOV||D, A||[D] <- [A]|
Explanation – Registers A, H, D are used for general purpose.
- LDA is used to load accumulator direct using 16-bit address (3 Byte instruction)
- MOV is used to transfer the data (1 Byte instruction)
- XCHG is used to exchange the data of both the register pair (H-L), (D-E) (1 Byte instruction)
- HLT is used to halt the program.