Square-Root Approximation

The circuit approximates sqrt(a^2 + b^2) without a multiplier. It computes x=max(abs(a), abs(b)), y=min(abs(a), abs(b)), then max(x, x - x/8 + y/2). Divisions by 8 and 2 are right shifts. i_start launches the calculation when o_ready='1'; o_r is valid when o_ready returns to '1'.