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Transfer Accumulator to X Index
Opcode: TAX
Operation: A → X
Status Register: Status-List.png

TAX (Transfer Accumulator to X Index) transfers the value in the accumulator to the X index. The reverse of this opcode is TXA.


This pseudo C code shows how the TAX opcode functions when it is executed.

unsigned src = A;             // Load the value of the accumulator as an unsigned byte.
SET_NEGATIVE(src);            // Sets the Negative Flag equal to the 7th bit.
SET_ZERO(src);                // Sets the Zero Flag if the Operand is $#00, otherwise clears it.
X = (src);                    // Stores the value of the Accumulator into the X index.

Addressing Modes

Addressing Mode Assembly Language Form Opcode # Bytes # Cycles
Implied TAX AA 1 2