LDX (LoaD X register)¶

X = [operand]

LDX (LoaD X register) is an instruction that loads a value from memory into the X register. The operand can be either an immediate value, a memory location specified by its address, or a memory location specified by an indexed indirect or indirect indexed address.

The result is stored in the X register, and the Zero and Negative flags are set based on the result.

Addressing Modes¶

Mode	Syntax	Bytes	Cycles
Immediate	LDX #const	`A2 nn`	2
ZeroPage	LDX zp	`A6 nn`	3
ZeroPage+Y	LDX zp,y	`B6 nn`	4
Absolute	LDX addr	`AE ll hh`	4
Absolute+Y	LDX addr,y	`BE ll hh`	4-5

Flags Affected¶

N (Negative) – Set if the loaded value has the most significant bit set (i.e., is negative); otherwise, it is cleared.
Z (Zero) – Set if the loaded value is zero; otherwise, it is cleared.

Examples¶

Load a Constant into the X Register¶

    LDX #10    ; load X with constant 10

Load a Value from a Memory Location¶

    LDX $20    ; load X with the value at memory location $20

Load a Value from a Memory Location with an Offset¶

    LDY #2     ; load Y with 2
    LDX $10,Y  ; load X with the value at memory location $12 ($10 + Y)