Intel® FPGA Power and Thermal Calculator User Guide

ID 683445
Date 6/20/2022
Public

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4.7. Intel® FPGA PTC - DSP Page

Each row in the DSP page of the Intel® FPGA Power and Thermal Calculator ( Intel® FPGA PTC) represents a DSP design module where all instances have the same configuration, clock frequency, toggle percentage, and register usage.
Figure 16. DSP Page of the Intel® FPGA PTC


Table 8.  DSP Page Information
Column Heading Description
Module

Enter a name for the DSP module in this column. This is an optional value.

Configuration Select the DSP block configuration for the module.
# of Instances

Enter the number of DSP block instances that have the same configuration, clock frequency, toggle percentage, and register usage. This value is not necessarily equal to the number of dedicated DSP blocks you use. For example, it is possible to use two 18 × 18 simple multipliers that are implemented in the same DSP block in the FPGA devices. In this case, the number of instances would be two.

To determine the maximum number of instances you can fit in the device for any particular mode, follow these steps:

  1. Open the “Variable Precision DSP Blocks” chapter of the appropriate device family handbook.
  2. In the “Number of DSP Blocks” table, take the maximum number of DSP blocks available in the device for the mode of operation.
  3. Divide the maximum number by the “# of Mults” for that mode of operation from the “DSP Block Operation Modes” table. The resulting value is the maximum number of instances supported by the device.
Clock Freq (MHz)

Enter the clock frequency for the module (in MHz). This value is limited by the maximum frequency specification for the device family.

Clock Enable % Specifies the percentage of time that the DSP block is enabled. ( Intel® Agilex™ devices only.)
Toggle %

Enter the average percentage of DSP data outputs toggling on each clock cycle. The toggle percentage ranges from 0 to 50%. The default value is 12.5%. For a more conservative power estimate, use a higher toggle percentage.

50% corresponds to a randomly changing signal, since half the time the signal holds the same value and thus not transition. This is considered the highest meaningful toggle rate for a DSP block.

Preadder? Select Yes if the PreAdder function of the DSP block is turned on.
Coefficient? Select Yes if the Coefficient function of the DSP block is turned on.
Registered Stages

Select number of the registered stages. Permitted values depend on the selected mode; some modes, such as floating-point multiply and accumulate cannot have 0 register stages..

  • 0—None
  • 1—Input
  • 2—Input and Output
  • 3—Input, Output, and Multiplier
  • 4— Input, Output, Multiplier, and Pipeline Stage 2
  • 5—Input, Output, Multiplier, Pipeline Stage 2, and Floating-Point Adder
Power (W) Routing

Indicates the power dissipation due to estimated routing (in W).

Routing power depends on placement and routing, which is a function of design complexity. The values shown represent the routing power estimate based on observed behavior across more than 100 real-world designs.

Block

Indicates the estimated power consumed by the DSP blocks (in W).

Total

Indicates the estimated power (in W), based on information entered into the Intel® FPGA PTC. It is the total power consumed by the DSP blocks and is equal to the routing power and block power.

User Comments Enter any comments. This is an optional entry.

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