Intel® Stratix® 10 Variable Precision DSP Blocks User Guide

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

10.2. Native Floating Point DSP Intel® Stratix® 10 FPGA IP Core Supported Operational Modes

Table 56.  Operational Modes Supported by Native Floating Point DSP Intel® Stratix® 10 FPGA IP Core
Operational Modes Description Supported Exception Flags
Multiply mode

This mode performs single precision multiplication operation.

This mode applies the following equation:
  • Out = Ay * Az
  • mult_overflow
  • mult_underflow
  • mult_inexact
  • mult_invalid
Add mode This mode performs single precision addition or subtraction operation.
This mode applies the following equations:
  • Out = Ay + Ax
  • Out = Ay - Ax
  • adder_overflow
  • adder_underflow
  • adder_inexact
  • adder_invalid
Multiply Add mode

This mode performs single precision multiplication, followed by addition or subtraction operations.

This mode applies the following equations:
  • Out = (Ay * Az) - chainin
  • Out = (Ay * Az) + chainin
  • Out = (Ay * Az) - Ax
  • Out = (Ay * Az) + Ax
  • mult_overflow
  • mult_underflow
  • mult_inexact
  • mult_invalid
  • adder_overflow
  • adder_underflow
  • adder_inexact
  • adder_invalid
Multiply Accumulate mode

This mode performs floating-point multiplication followed by floating-point addition or subtraction with the previous multiplication result.

This mode applies the following equations:
  • Out(t) = [Ay(t) * Az(t)] - Out (t-1) when accumulate signal is driven high.
  • Out(t) = [Ay(t) * Az(t)] + Out (t-1) when accumulate port is driven high.
  • Out(t) = Ay(t) * Az(t) when accumulate port is driven low.
Vector Mode 1

This mode performs floating-point multiplication followed by floating-point addition or subtraction with the chainin input from the previous variable DSP Block.

This mode applies the following equations:
  • Out = (Ay * Az) - chainin, chainout = Ax
  • Out = (Ay * Az) + chainin , chainout = Ax
  • Out = (Ay * Az) , chainout = Ax
Vector Mode 2 This mode performs floating-point multiplication where the multiplication result is directly fed to chainout. The chainin input from the previous variable DSP Block is then added or subtracted from input Ax as the output result.

This mode applies the following equations:

  • Out = Ax - chainin , chainout = Ay * Az
  • Out = Ax + chainin , chainout = Ay * Az
  • Out = Ax , chainout = Ay * Az