code: function xor (cpu, n) {
      const r = cpu.a ^ n;
  
      cpu.f = 0;
      if ((r & 0xff) == 0) cpu.f |= FLAG_Z;
  
      return r;
  }
docs: XOR n
  
  Description:
  Logical exclusive OR n with register A, result in A.
  
  Use with:
  n = A, B, C, D, E, H, L, (HL), #
  
  Flags affected:
  Z - Set if result is zero.
  N - Reset.
  H - Reset.
  C - Reset.
  
  Opcodes:
  Instruction    Parameters    Opcode    Cycles
  XOR            A             AF        4
  XOR            B             A8        4
  XOR            C             A9        4
  XOR            D             AA        4
  XOR            E             AB        4
  XOR            H             AC        4
  XOR            L             AD        4
  XOR            (HL)          AE        8
  XOR            #             EE        8