8085 program to generate Fibonacci series
Problem – Write an assembly language program in 8085 microprocessor to generate Fibonacci series.
Example – Assume Fibonacci series is stored at starting memory location 3050.
Note – This program generates Fibonacci series in hexadecimal numbers.
Algorithm –
- Initialize register H with 30 and register L with 50, so that indirect memory M points to memory location 3050.
- Initialize register B with 00, register C with 08 and register D with 01.
- Move the content of B in M.
- Increment M by 1 so that M points to next memory location.
- Move the content of D in M.
- Move the content of B in accumulator A.
- Add the content of D in A.
- Move the content of D in B.
- Move the content of A in D.
- Increment M by 1 so that M points to next memory location.
- Move the content of A in M.
- Decrements C by 1.
- Jump to memory location 200C if ZF = 0 otherwise Halt the program.
Program –
| MEMORY ADDRESS | MNEMONICS | COMMENT |
|---|---|---|
| 2000 | LXI H, 3050 | H <- 30, L <- 50 |
| 2003 | MVI C, 08 | C <- 08 |
| 2005 | MVI B, 00 | B <- 00 |
| 2007 | MVI D, 01 | D <- 01 |
| 2009 | MOV M, B | M <- B |
| 200A | INX H | M <- M + 01 |
| 200B | MOV M, D | M <- D |
| 200C | MOV A, B | A <- B |
| 200D | ADD D | A <- A + D |
| 200E | MOV B, D | B <- D |
| 200F | MOV D, A | D <- A |
| 2010 | INX H | M <- M + 01 |
| 2011 | MOV M, A | M <- A |
| 2012 | DCR C | C <- C – 01 |
| 2013 | JNZ 200C | Jump if ZF = 0 |
| 2016 | HLT | END |
Explanation – Registers A, B, C, D, H, L are used for general purpose.
- LXI H 3050: assigns 30 to H and 50 to L.
- MVI B, 00: assigns 00 to B.
- MVI C, 08: assigns 08 to C.
- MVI D, 01: assigns 01 to D.
- MOV M, B: moves the content of B in M.
- INX H: increment M by 1.
- MOV M, D: moves the content of D in M.
- MOV A, B: moves the content of B in A.
- ADD D: add the content of D and A. Store the result in A.
- MOV B, D: moves the content of D in B.
- MOV D, A: moves the content of A in D.
- INX H: increment M by 1.
- MOV M, A: moves the content of A in M.
- DCR C: decrements C by 1.
- JNZ 200C: jump to memory location 200C if ZF = 0.
- HLT: stops executing the program and halts any further execution.
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