Variable Precision DSP Blocks User Guide: Agilex™ 5 FPGAs and SoCs

ID 813968
Date 9/20/2024
Public
Document Table of Contents

3.1.2. Multiplier Adder Sum Mode

The multiplier adder sum mode uses these equations:

  • resulta = (bx × by) + (ax × ay) to calculate the sum of the two 18 x 19 multiplications.
  • resulta = (bx × by) – (ax × ay) to calculate the difference of the two 18 x 19 multiplications.
Figure 22. One Sum of Two 18 x 18 or 18 × 19 Multipliers with One Variable Precision DSP Block for Agilex™ 5 Devices

In this figure, the variable is defined as follows:

  • n = 19 for 18 × 19 signed operands
  • n = 18 for 18 × 18 unsigned operands

Set the SUB dynamic control signal to high to calculate the difference of the two 18 × 19 multiplications.