Intel® Stratix® 10 Variable Precision DSP Blocks User Guide

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

2.6. Adder or Subtractor for Fixed-Point and Floating-Point Arithmetic

Depending on the operational mode, you can use the adder or subtractor as follows:

  • One 38-bit adder for fixed-point arithmetic addition and subtraction between two multipliers within a DSP block.
  • One floating-point arithmetic single precision adder or subtractor.
Use the dynamic SUB port to select the adder to perform addition or subtraction operation for fixed-point arithmetic.
Table 7.  Adder Operations with SUB Dynamic Control Signal
Operation Description SUB Signal
Addition Adds the results of the two multipliers within one DP block. 0
Subtraction Subtracts the results between two multipliers within the same DSP block. 1

The dynamic SUB port is not supported in floating-point arithmetic.