Stacked-Die NIC Circuitry for Flexible Packet Processing

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Solution Overview

Problem

Conventional network interface cards face challenges in balancing flexibility with performance, power consumption, and area constraints, as they are either inflexible ASICs or power-hungry FPGAs.

Innovation Solution

A network interface controller (NIC) is implemented using a stacked die configuration, where a programmable integrated circuit die is stacked on top of an application-specific integrated circuit (ASIC) die, combining the flexibility of programmable logic with the performance and efficiency of ASICs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an ASIC implementation is used, then performance and power efficiency are improved, but flexibility and configurability deteriorate

Engineering Contradiction:
ImproveperformanceVSAvoidflexibility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The network interface card is divided into two separate dies: an ASIC die containing fixed-function network interface controllers and a programmable logic die containing reconfigurable logic. This segmentation allows each die to be optimized for its specific function, with the ASIC die providing high-performance fixed functions and the programmable die providing flexibility, thereby resolving the contradiction between performance and adaptability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent combines ASIC and programmable logic technologies into a single integrated network interface card through die stacking. The fixed-function network interface controllers on the ASIC die are merged with reconfigurable logic on the programmable die, creating a hybrid system that simultaneously delivers the performance benefits of ASIC and the flexibility benefits of programmable logic.

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If an FPGA implementation is used, then flexibility and configurability are improved, but performance and power efficiency deteriorate

Engineering Contradiction:
ImproveconfigurabilityVSAvoidperformance
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The system segments network processing functions into fixed-function components on the ASIC die and reconfigurable components on the programmable die. This allows performance-critical fixed functions to be implemented in high-performance ASIC logic while flexibility-requiring functions are implemented in reconfigurable logic, resolving the performance penalty typically associated with FPGA implementations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the network interface card have different qualities: the ASIC die provides high-performance fixed-function processing for standard network operations, while the programmable die provides configurable logic for custom processing requirements. This local differentiation allows each part to excel at its specific function, overcoming the universal performance limitations of pure FPGA designs.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If more die area is used, then functionality and configurability are improved, but area and cost increase

Engineering Contradiction:
ImprovefunctionalityVSAvoiddie area
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent transitions from a single-die two-dimensional layout to a multi-die three-dimensional stacked configuration. By stacking the ASIC die and programmable logic die vertically, the system achieves enhanced functionality and configurability without proportionally increasing the footprint area, as the additional die area is utilized in the vertical dimension through interconnect structures.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3929758B1Stacked die network interface controller circuitry
Publication Date: 2025.04.23 INTEL CORP
  • EP3929758B1 patent drawingFigure 1
  • EP3929758B1 patent drawingFigure 2
  • EP3929758B1 patent drawingFigure 3

AI summary

A smart network interface controller (NIC) implemented using a stacked die configuration is provided. The NIC may include user-customizable networking circuits formed in a top programmable die and primitive network function blocks formed in a bottom application-specific integrated circuit (ASIC) die. The top programmable die may provide a flexible packet processing pipeline to facilitate efficient control and data communication between the user-customizable networking circuits and the primitive network function blocks. The bottom ASIC die may also include an array of memory blocks operable as lookup tables and intermediate buffers for other network processing circuitry in the NIC. A NIC configured in this way provides both performance, power, and area benefits and superior customer configurability.