Bits and bytes basic definitions
On [#harris-harris-digital-design], chapter 1.
Bits: most basic unit, those are the actual 0
s and 1
s
Byte: a group of 8 bits. I.e., 10101010
. A pair of hexadecimal numbers hold 1 byte. I.e, AA
is the same as 10101010
Most significant bit: bit on the leftmost part of the number
Least significant bit: bit on the rightmost part of the number
Most significant byte: byte on the leftmost part of the sequence
Least significant byte: byte on the rightmost part of the sequence
Overflow: when we misrepresent a number due to the lack of bits. Let's say we are adding to binaries of 4 bits, and the result would force us to carry over a 1
to a 5th bit. We'd still be able to represent the number with only 4 bits, thus overflowing
Unsigned numbers: Numbers have no sign. The examples we've seen so far are all unsigned. Unsigned binaries go from 0
to 2^n - 1
, n
is the bit count.
Signed numbers: When the most significant bit represents a signal, not a number. I.e.,: $$0010 = +2, 1010 = -2$$
Signed binaries go from -1 * (2^{n - 1} - 1)
to 2^{n - 1} - 1
Two complement numbers: #todo definition and note
To know more about number notations, go to 202103151907 Decimal, binary and hexadecimal
[#harris-harris-digital-design]: Harris, David Money, and Sarah L. Harris. Digital Design and Computer Architecture. Second edition. Amsterdam: Elsevier, 2013.