Assembly Tutorial

# Binary Representation in Assembly Language

Binary representation in assembly language refers to the way that data and instructions are stored in memory and executed by the computer. Assembly language programmers need to understand binary representation in order to write efficient and correct code.

## Binary Numbers

Binary numbers are numbers that are represented using only two digits: 0 and 1. This is in contrast to decimal numbers, which are represented using ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.

Binary numbers are often represented as strings of bits, where each bit is either a 0 or a 1. For example, the binary number 1010 represents the decimal number 10.

## Binary Representation in Assembly Language

Assembly language programmers use binary numbers to represent data and instructions. Data is stored in memory as binary numbers, and instructions are executed by the computer as binary numbers.

For example, the following assembly language instruction stores the binary number 1010 in the register EAX:

mov eax, 1010h

The mov instruction is used to move data from one location to another. In this example, the mov instruction is moving the binary number 1010 from the immediate operand to the register EAX.

## Different types of data in binary

The following assembly language instructions show how to represent different types of data in binary:

; Store the binary number 1010 in the register EAX. mov eax, 1010h ; Store the ASCII character 'A' in the register AL. mov al, 'A' ; Store the floating-point number 3.14159 in the register XMM0. mov xmm0, 3.14159 ; Store the address of the string "Hello, world!" in the register EDI. mov edi, my_string

## Different types of instructions in binary

The following assembly language instructions show how to execute different types of instructions in binary:

; Add the value of the register EAX to the value of the register EBX. add eax, ebx ; Subtract the value of the register ECX from the value of the register EDX. sub edx, ecx ; Multiply the value of the register ESI by the value of the register EDI. mul esi, edi ; Divide the value of the register EAX by the value of the register EBX. div ebx ; Jump to the address stored in the register EDI. jmp edi

## Registers and Binary Operations

Binary numbers are commonly used in registers for arithmetic and logical operations.

; Load binary values into registers mov eax, 1010b ; Binary representation of 10 add eax, 1100b ; Binary representation of 12

## Bitwise Operations

Bitwise operations manipulate individual bits for tasks such as setting, clearing, or toggling.

; Set the 3rd bit to 1 or eax, 0b00000100

## Binary Representation of Memory Addresses

Memory addresses are often represented in binary to indicate the location of data in memory.

## Binary Representation of Instructions

Machine instructions and opcodes are often represented in binary for execution by the CPU.

; Binary representation of a simple MOV instruction 10001011 11001001

## Floating-Point Representation

Floating-point numbers are represented using binary for both the mantissa and exponent.

; Binary representation of the floating-point number 3.14 01000000010010001111010111000010

### Conclusion

Understanding binary representation is essential for programming in assembly language as it forms the basis for numeric data manipulation and control flow within a computer system. The specific conventions and representations may vary between different assembly languages and architectures.