|Transfer Accumulator to Y Index
TAY (Transfer Accumulator to Y Index) transfers the value in the accumulator to the Y index. The reverse of this opcode is TYA.
This pseudo C code shows how the TAY 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.
Y = (src); // Stores the value of the Accumulator into the Y index.