Arria® 10 Core Fabric and General Purpose I/Os Handbook

ID 683461
Date 7/08/2024
Public
Document Table of Contents

3.4.3. Pre-Adder for Fixed-Point Arithmetic

Each variable precision DSP block has two 19-bit pre-adders. You can configure these pre-adders in the following configurations:

  • Two independent 19-bit pre-adders
  • One 27-bit pre-adder

The pre-adder supports both addition and subtraction in the following input configurations:

  • 18-bit (signed or unsigned) addition or subtraction for 18 x 19 mode
  • 26-bit addition or subtraction for 27 x 27 mode

When both pre-adders within the same DSP block are used, they must share the same operation type (either addition or subtraction).