SiP Clock Alignment Loop for Interconnect Delay Compensation

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Solution Overview

Problem

System-in-package (SiP) devices face challenges in aligning clock signals across integrated circuits due to interconnect delays, which cause latency penalties in high-performance applications, especially when synchronous elements must operate simultaneously.

Innovation Solution

The implementation of an adaptive clock signal alignment mechanism that compensates for interconnect delays by dynamically measuring and adjusting local clock signals to align with a source clock signal, using a clock alignment loop circuit that includes a clock aligning block, clock control block, and clock distribution network, ensuring synchronous communication across multiple SiP devices within a single clock domain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If clock signals are distributed across multiple SiP devices using traditional interconnect techniques, then device integration is achieved, but clock signal alignment deteriorates due to interconnect delays

Engineering Contradiction:
Improvedevice integrationVSAvoidclock signal alignment
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent implements a feedback mechanism where skew information is measured between clock signals from different SiP devices and used to dynamically adjust delay elements. The system continuously monitors clock signal alignment and modifies delay compensation in real-time to maintain synchronization despite varying interconnect delays.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent employs dynamic delay adjustment mechanisms that can adaptively change the delay characteristics of clock signal paths. Variable delay elements are controlled based on measured skew information, allowing the system to dynamically compensate for interconnect delays and maintain clock signal alignment across SiP devices.

Inventive Principle:
Principle #15Dynamics

2Speed

If high-speed operation is implemented in SiP devices, then performance is improved, but latency penalties increase due to clock skew

Engineering Contradiction:
Improveoperation speedVSAvoidlatency
Core Design Contradiction:
SpeedVSLoss of time

Solution Approach 1:

The patent applies preliminary delay compensation by pre-adjusting clock signal paths based on measured skew information before data transmission occurs. Delay elements are configured in advance to compensate for known interconnect delays, ensuring that clock signals arrive at synchronous elements simultaneously and eliminating latency penalties associated with clock skew.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If multiple synchronous elements operate simultaneously across SiP devices, then functionality is enhanced, but clock synchronization becomes more difficult

Engineering Contradiction:
Improvesynchronous communication capabilityVSAvoidclock alignment complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the clock alignment problem by implementing independent delay adjustment mechanisms for each SiP device or clock domain. Rather than attempting to synchronize all elements globally, the system divides the problem into manageable segments, allowing each segment to independently adjust its clock signal timing based on local skew measurements.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3096199B1Clock signal alignment for system-in-package (SIP) devices
Publication Date: 2024.11.20 NXP USA INC
  • EP3096199B1 patent drawingFigure 1
  • EP3096199B1 patent drawingFigure 2
  • EP3096199B1 patent drawingFigure 3

AI summary

A method embodiment of the present disclosure includes receiving a delay value associated with an interconnect delay that is measured across interconnect circuitry communicatively coupling a host semiconductor device with a semiconductor device. The method also includes delaying a local clock signal by an amount of delay indicated by the delay value to produce a delayed local clock signal. The method also includes receiving a delayed source clock signal, where the delayed source clock signal is received from the host semiconductor device via the interconnect circuitry. The method also includes outputting a master clock signal based on a comparison of the delayed source clock signal and the delayed local clock signal, where the master clock signal is utilized to generate one or more aligned clock signals on the semiconductor device that are aligned with a source clock signal generated on the host semiconductor device.