code: function rrc (cpu, n) {
      const r = n >> 1 | n << 7;
  
      cpu.f = 0;
      if ((r & 0xff) == 0) cpu.f |= FLAG_Z;
      if ((n & 1) != 0) cpu.f |= FLAG_C;
  
      return r;
  }
docs: RRC n
  
  Description:
  Rotate n right. Old bit 0 to Carry flag.
  
  Use with:
  n = A, B, C, D, E, H, L, (HL)
  
  Flags affected:
  Z - Set if result is zero.
  N - Reset.
  H - Reset.
  C - Contains old bit 0 data.
  
  Opcodes:
  Instruction    Parameters    Opcode    Cycles
  RRC            A             CB 0F     8
  RRC            B             CB 08     8
  RRC            C             CB 09     8
  RRC            D             CB 0A     8
  RRC            E             CB 0B     8
  RRC            H             CB 0C     8
  RRC            L             CB 0D     8
  RRC            (HL)          CB 0E     16