Most significant bit

In computing, bit numbering (or sometimes bit endianness) is the convention used to identify the bit positions in a binary number or a container of such a value. The bit number starts with zero and is incremented by one for each subsequent bit position. In computing, bit numbering (or sometimes bit endianness) is the convention used to identify the bit positions in a binary number or a container of such a value. The bit number starts with zero and is incremented by one for each subsequent bit position. In computing, the least significant bit (LSB) is the bit position in a binary integer giving the units value, that is, determining whether the number is even or odd. The LSB is sometimes referred to as the low-order bit or right-most bit, due to the convention in positional notation of writing less significant digits further to the right. It is analogous to the least significant digit of a decimal integer, which is the digit in the ones (right-most) position. It is common to assign each bit a position number, ranging from zero to N-1, where N is the number of bits in the binary representation used. Normally, this is simply the exponent for the corresponding bit weight in base-2 (such as in 231..20). Although a few CPU manufacturers assign bit numbers the opposite way (which is not the same as different endianness), the term least significant bit itself remains unambiguous as an alias for the unit bit.