Channel Analysis for High-Speed Serial Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed microprocessor data transmission poses challenges for traditional interconnects, leading to increased simulation time and insufficient prediction of realistic eye patterns due to inter-symbol interference in serial data link designs, where traditional full-time domain circuit simulation is inadequate and requires costly large bit streams.
Innovation Solution
Channel analysis is employed to characterize the interconnects and active devices together, using impulse response to determine optimal filter settings, such as pre-emphasis and Decision Feedback Equalization filters, and integrating these into simulation algorithms to mitigate signal degradation and inter-symbol interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional full-time domain circuit simulation is used for high-speed serial data links, then simulation accuracy can be maintained, but simulation time increases dramatically from seconds to hours
Solution Approach 1:
The patent segments the simulation process into two distinct phases: (1) a comprehensive full-time domain circuit simulation performed once during design to capture accurate impulse responses and channel characteristics, and (2) a streamlined simulation mode for subsequent iterations that uses the pre-captured characteristics to rapidly evaluate design modifications. This segmentation allows the system to maintain accuracy where needed while achieving speed improvements of 100x or more for routine simulations.
Solution Approach 2:
The patent performs preliminary action by conducting a complete full-time domain simulation in advance to extract and store channel impulse responses, transfer functions, and other characteristic parameters. These pre-computed characteristics are then reused in subsequent simulations, eliminating the need to repeat the computationally intensive full simulation for every design iteration. This preliminary characterization enables rapid evaluation of filter settings and design changes without sacrificing accuracy.
2Measurement precision
If large bit streams are simulated to overcome inter-symbol interference effects, then realistic eye patterns can be predicted, but simulation cost and time increase significantly
Solution Approach 1:
The patent uses copying by creating an accurate mathematical model (impulse response) of the channel characteristics from a single full simulation, then using this copied model to generate eye patterns without requiring lengthy bit streams. The impulse response captures the essential inter-symbol interference effects, allowing realistic eye pattern prediction through convolution with shorter test sequences, thereby reducing the quantity of bits needed from hundreds of thousands to manageable lengths.
3Device complexity
If serial data link design is used instead of traditional buses, then interconnect complexity is reduced and data throughput is boosted, but signal degradation and inter-symbol interference become significant challenges
Solution Approach 1:
The patent implements feedback by using the simulated eye pattern results and channel characteristics to iteratively optimize filter settings (such as equalization filters and pre-emphasis filters). The simulation provides feedback on signal quality metrics, which are then used to adjust filter parameters to compensate for channel-induced signal degradation. This closed-loop optimization ensures that the simplified serial interconnect achieves the required signal integrity and reliability.
Solution Approach 2:
The patent applies parameter changes by systematically varying filter settings, equalization parameters, and transmission characteristics based on the simulated channel response. The optimization process adjusts these parameters to maximize eye pattern quality and minimize inter-symbol interference effects, thereby maintaining signal integrity despite the simplified serial interconnect structure.
Data Source
AI summary
A system, method, computer program and article of manufacture for channel analysis. Channel analysis is a multi gigahertz capacity time domain circuit simulation which uses the impulse response of the channel to determine optimum filter settings and to produce wave form plots in a fraction of the time of circuit simulation.