In this program, we are going to write an assembly language program to Find the 1’s complement of a Number in 8085 microprocessor with a program flow chart and explanation of the program.

**1’s complement of a Number in 8085**

**Program Statement**

Find the 1’s complement of the number stored at memory location C200H and store the complemented number at memory location C300H.

**Explanation of Program**

- 1’s complement of a number means to invert each bit of that number. So our task is to complement each bit of the number.
- We will first load the number in the accumulator whose 1’s complement is to be found.
- Then using CMA instruction we will complement the accumulator. This is 1’s complement of the number.
- Store the result at memory location C300H.
- Let
**A = AAH** - i.e. A: 10101010
- 1’s complement of A: 01010101
- Thus, 1’s complement of A is
**55H**.

- Let

**Assembly Language Program**

Instruction | Comments | Operation |
---|---|---|

LDA C200H | Load the number in the accumulator from the C200H memory address. | A = AA H |

CMA | Complement the number | A = 55 H |

STA C300H | Store the 1’s complement of the number at memory location C300H. | C300H = H |

HLT | Terminate program execution | Stop |