ST_PROCESS — special-case classification
1. avg is NaN / ±Inf → output +0.0
2. sample is NaN / ±Inf → output +1.0
3. sample ≥ avg (bit-compare val[14:0] ≥ avg[14:0]) → clamp to +1.0
4. sample is zero / denormal → output +0.0
5. None of the above → divide path (22-cycle restoring division)
ST_DIV_INIT + ST_DIVIDING — mantissa long division (22 cycles)
Dividend = {sample_mantissa_full, 11 zeros} (22 bits).
Divisor = avg_mantissa_full (11 bits).
Each cycle shifts in one dividend bit from the MSB down. Green rows = quotient bit = 1.