Intel Agilex® 7 Variable Precision DSP Blocks User Guide

ID 683037
Date 4/11/2023
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3.1.4.1. 18 × 19 Multiplication Summed with 36-Bit Input Mode

Intel® Agilex™ 7 variable precision DSP blocks support one 18 × 19 multiplication summed to a 36-bit input.

The 18 × 19 multiplication summed with 36-bit input mode uses the equations:
  • resulta = (ax * ay) + bx to sum the 18 x 19 multiplication with 36-bit input.
  • resulta = (ax * ay) - bx to subtract the 18 x 19 multiplication with 36-bit input.

Use the upper multiplier to provide the input for an 18 × 19 multiplication, while the bottom multiplier is bypassed. The bx[35..0] signals the 36-bit input operand.

Use the SUB dynamic control signal to control the adder to perform addition or subtraction operation.

Figure 22. One 18 x 19 Multiplication Summed with 36-Bit Input Mode for Intel® Agilex™ 7 Devices

In this figure, the variable is defined as follows:

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