Fixed-point with fixed_pkg

Understand ufixed, sfixed, fractional bits, resize and conversion to std_logic_vector.

Fixed-point arithmetic assigns a known weight to every bit, including fractional bits. It represents gains and values such as 0.75 or -1.25 in a format chosen for range and precision.

For eight bits in Q4.4, four positions are integer and four fractional. The value is the encoded integer divided by . Q conventions may include or exclude the sign in the first number; state which convention you use.