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

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

6.2.1. Pre-adder

With pre-adder, additions or subtractions are done prior to feeding the multiplier.

There are five pre-adder modes:

  • Simple mode
  • Coefficient mode
  • Input mode
  • Square mode
  • Constant mode
Note: The pre-adder features; Input mode, Square mode, and Constant mode will be implemented as an Logical Element (LE) via Multiply Adder IP Core while the pre-adder features; Simple mode and Coefficient mode will be inferred as DSP block.
Note: When pre-adder is used (pre-adder coefficient/input/square mode), all data inputs to the multiplier must have the same clock setting.