TAY

From C64-Wiki
Jump to: navigation, search

TAY (short for "Transfer Accumulator to Y") is the mnemonic for a machine language instruction which transfers ("copies") the contents of the accumulator into the Y index register.

Addressing mode[edit]

Opcode Addressing
mode
Assembler
format
Length
in bytes
Number of
cycles
Dec Hex
168 A8 Implied TAY 1 2

TAY only supports the Implied addressing mode, as shown in the table at right.

CPU flags[edit]

TAY affects 2 of the CPU's status flags:

  • The negative status flag is set if the byte transferred is negative, i.e. has it's most significant bit set.
  • The zero flag is set if the byte transferred is zero, or cleared if it is non-zero.