Q. Write an 8085 program and draw a flowchart to Sum a series of 8-bit numbers.(8085 Microprocessor Program)
Flowchart/Algorithm
Program
| Address | Mnemonics | Operand | Opcode | Comments |
| 2000 | LXI | H, 3000H | 21 | Load H-L pair with address 3000H. |
| 2001 | 00 | |||
| 2002 | 30 | |||
| 2003 | MOV | C, M | 4E | Move the counter from memory to reg. C. |
| 2004 | MVI | A, 00H | 3E | Initialize accumulator with 00H. |
| 2005 | 00 | |||
| 2006 | INX | H | 23 | Increment H-L pair. |
| 2007 | MOV | B, M | 46 | Move next number from memory to reg. B. |
| 2008 | ADD | B | 80 | Add B with A. |
| 2009 | DCR | C | 0D | Decrement counter. |
| 200A | JNZ | 2006H | C2 | Jump to address 2006H if the counter is not zero. |
| 200B | 06 | |||
| 200C | 20 | |||
| 200D | INX | H | 23 | Increment H-L pair. |
| 200E | MOV | M, A | 77 | Move the result from reg. A to memory. |
| 200F | HLT | 76 | Halt |
Output
Before Execution:
3000H: 05H (Counter)
3001H: 02H
3002H: 04H
3003H: 03H
3004H: 02H
3005H: 01H
After Execution:
3006H: 0CH
Program Explanation
- This program finds the sum of numbers in an array.
- In order to find the sum of numbers, first, the counter must be initialized with the size of an array and accumulator must be initialized to zero.
- Then, the first number is moved to register B and added with the accumulator.
- After addition, the counter is decremented and checked whether it has reached zero. If it has, the loop terminates otherwise, the next number is moved to register B and added.
- Let us assume that the memory location 3000H stores the counter. The next memory locations store the array.
- Initially, H-L pair is loaded with the address of the counter and is moved to register C.
- Accumulator is initialized with 00H.
- Then, H-L pair is incremented to point to the first number in the array and it is moved to register B.
- Register B is added to the accumulator and the result is stored in the accumulator.
- Then, the counter is decremented and checked whether it has become zero.
- If it hasn’t become zero, it means there are numbers left in the array. In this case, the control jumps back to increment the H-L pair and moves the next number to register B.
- This process continues until counter becomes zero, i.e. all the numbers in the array are added.
- At last, H-L pair is incremented and the result is moved from accumulator to memory.
