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8085 PROGRAM TO COMPARE TWO NUMBERS
When working with microprocessors like the 8085, one common task is to compare two numbers to determine their relationship. This can be useful in various applications, such as sorting algorithms, decision-making processes, and conditional branching in programming. In this article, we will explore how to write an 8085 program to compare two numbers.
Understanding the 8085 Microprocessor
The 8085 is an 8-bit microprocessor that was introduced by Intel in 1976. It has a set of instructions that can be used to perform various operations, including arithmetic, logic, and data transfer. One of the key instructions for comparison is the CMP (Compare) instruction, which is used to compare two numbers without changing the contents of the accumulator.
Writing the Program
Let’s consider a simple program to compare two numbers stored in memory locations 2000H and 2001H.
. Here is the assembly code for the program:
- Load the first number into the accumulator
- Move the accumulator contents to register B
- Load the second number into the accumulator
- Compare the contents of the accumulator with the contents of register B
- If the numbers are equal, jump to a specific memory location
- If the first number is greater, jump to a different memory location
- If the second number is greater, jump to another memory location
By following these steps, we can effectively compare two numbers using the 8085 microprocessor.
Example Program
Here is an example program in assembly language to compare two numbers:
“`assembly
LDA 2000H ; Load the first number into the accumulator
MOV B, A ; Move the accumulator contents to register B
LDA 2001H ; Load the second number into the accumulator
CMP B ; Compare the contents of the accumulator with the contents of register B
JZ EQUAL ; If the numbers are equal, jump to the EQUAL label
JC FIRST ; If the first number is greater, jump to the FIRST label
JMP SECOND ; If the second number is greater, jump to the SECOND label
EQUAL: ; Equal numbers
; Your code here
JMP EXIT
FIRST: ; First number is greater
; Your code here
JMP EXIT
SECOND: ; Second number is greater
; Your code here
JMP EXIT
EXIT: ; End of program
HLT
“`
Conclusion
In conclusion, writing an 8085 program to compare two numbers involves loading the numbers into the accumulator, using the CMP instruction to compare them, and branching based on the result. By understanding the instructions and registers of the 8085 microprocessor, we can effectively implement comparison logic in our programs. This can be a valuable skill for programmers working with embedded systems and low-level programming.
