Intel® Stratix® 10 Variable Precision DSP Blocks User Guide

ID 683832
Date 8/13/2021
Public
Document Table of Contents

3.1.2. Multiplier Adder Sum Mode

The multiplier adder sum mode uses the 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 8. One Sum of Two 18 x 18 or 18 × 19 Multipliers with One Variable Precision DSP Block for Intel® Stratix® 10 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.