Immediate Addressing Mode

Immediate addressing mode allows programmers to directly specify constant values within instructions. It involves embedding the actual data directly into the instruction itself.

Example

Intel Syntax:

In Intel syntax, immediate operands are specified directly following the instruction mnemonic, separated by a comma. Immediate values can be represented in various formats, such as decimal, hexadecimal, or binary.

; Intel Syntax
mov eax, 10         ; Load the immediate value 10 into the eax register
add ebx, 0x20       ; Add the immediate hexadecimal value 0x20 to the ebx register
cmp ecx, 100        ; Compare the ecx register with the immediate value 100

In Intel syntax, immediate values are typically represented without any prefix for decimal values, with 0x prefix for hexadecimal values.

AT&T Syntax:

In contrast, AT&T syntax places the immediate operand after the instruction mnemonic, prefixed with a dollar sign ($).

# AT&T Syntax
mov $10, %eax       # Load the immediate value 10 into the eax register
add $0x20, %ebx     # Add the immediate hexadecimal value 0x20 to the ebx register
cmp $100, %ecx      # Compare the ecx register with the immediate value 100

In AT&T syntax, immediate values are often represented with a dollar sign prefix, followed by the value itself. Additionally, registers are prefixed with a percent sign (%) to distinguish them from immediate values.