code: def _int_to_words(self, pattern):
          
          try:
              bits_required = int(ceil(log(pattern, 2))) + 1
          except ValueError:
              # pattern == 0 (technically speaking, no bits are required to
              # transmit the value zero ;)
              bits_required = 1
          shifts = range(0, bits_required, self._spi.bits_per_word)[::-1]
          mask = 2 ** self._spi.bits_per_word - 1
          return [(pattern >> shift) & mask for shift in shifts]
docs: Given a bit-pattern expressed an integer number, return a sequence of
          the individual words that make up the pattern. The number of bits per
          word will be obtained from the internal SPI interface.