Visible to Intel only — GUID: kly1417140097088
Ixiasoft
3.1.3. The 18 × 18 Plus 36 Mode
When configured as 18 × 18 Plus 36 mode, the Cyclone® 10 GX Native Fixed Point DSP IP core enables only the top multiplier. This mode applies the equation of resulta = (ax * ay) + concatenate(bx[17:0],by[17:0]).
Figure 4. The 18 × 18 Plus 36 Mode Architecture
You must set Representation format for bottom multipliers y operand to unsigned when using this mode. When the input bus is less than 36-bit in this mode, you are required to provide the necessary signed extension to fill up the 36-bit input.