Hexadecimal in assembly language

Hexadecimal notation is a base-16 number system that uses the digits 0-9 and the letters A-F to represent numbers. It is a more compact and easier-to-read format than binary notation, which is why it is often used in assembly language programming.

Converting Between Hexadecimal and Decimal

To convert a hexadecimal number to decimal, simply multiply each digit by its corresponding power of 16 and add the results together. For example, to convert the hexadecimal number 1010h to decimal, we would do the following:

1010h = 1 * 16^ 3 + 0 * 16^ 2 + 1 * 16^ 1 + 0 * 16^ 0 = 4096 + 16 + 0 = 4112

To convert a decimal number to hexadecimal, we can use the following algorithm:

  1. Divide the decimal number by 16 and get the quotient and remainder.
  2. The remainder is the least significant digit of the hexadecimal number.
  3. Repeat steps 1 and 2 until the quotient is 0.
  4. The hexadecimal number is formed by writing the remainders in reverse order.

For example, to convert the decimal number 4112 to hexadecimal, we would do the following:

4112 / 16 = 257 and 0 (remainder) 257 / 16 = 16 and 1 (remainder) 16 / 16 = 1 and 0 (remainder) 1 / 16 = 0 and 1 (remainder) Hexadecimal number = 1010h

Using Hexadecimal Notation in Assembly Language

Assembly language programmers can use hexadecimal notation to represent data and instructions in a more compact and easier-to-read format. For example, the following assembly language instruction stores the hexadecimal value 1010h in the register EAX:

mov eax, 1010h

This instruction is equivalent to the following assembly language instruction, which stores the decimal value 4112 in the register EAX:

mov eax, 4112

Hexadecimal notation can also be used to represent addresses in memory. For example, the following assembly language instruction jumps to the address stored in the register EDI:

jmp edi

If the register EDI contains the hexadecimal value 1000h, then this instruction will jump to the address 4096 in memory.

Hexadecimal and Binary

Hexadecimal simplifies binary representation by grouping 4 bits into a single hexadecimal digit.

; Binary representation of the decimal number 10 1010 ; Hexadecimal representation: A

Registers and Hexadecimal

Hexadecimal numbers are commonly used in registers for clarity and compactness.

; Load hexadecimal values into registers mov eax, 0xA ; Hexadecimal representation of 10 add eax, 0xC ; Hexadecimal representation of 12

Memory Addresses in Hexadecimal

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

; Load data from the memory address 0x1A3F mov eax, [0x1A3F]

Hexadecimal Representation of Instructions

Machine instructions and opcodes can be represented in hexadecimal for readability.

; Hexadecimal representation of a simple MOV instruction 8B C9

Hexadecimal and Colors

Hexadecimal is commonly used to represent colors in HTML and graphics programming.

<!-- Hexadecimal representation of the color red --> <div style="color: #FF0000;">Hello, World!</div>


Understanding hexadecimal notation is crucial for programming in assembly language as it provides a concise and human-readable way to represent numerical values and memory addresses. The specific conventions and representations may vary between different assembly languages and architectures.