Programmable Parallel Data Preambles for Switching Noise Reduction
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Solution Overview
Problem
As data transmission speeds increase, existing DC balance coding systems, such as 8B/10B DC balance coding, face challenges in reducing simultaneous switching noise (SSN), which limits transmission speed and frequency due to fixed preamble usage, making it difficult to effectively manage noise variations with changing operating conditions.
Innovation Solution
A data communication system that generates or detects preambles with flexible lengths and patterns for each data line, allowing for adjustable preamble information to be programmed into a programmable unit, such as a mode register set or fuse circuit, to reduce SSN by creating an intermediate level of noise that is less than the maximum SSN created by DC balance encoded data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed preamble length is used in DC balance coding, then device complexity is reduced, but adaptability to different operating conditions deteriorates
Solution Approach 1:
The patent implements dynamic preamble length adjustment by introducing a preamble length control signal that selectively enables different preamble lengths (first length or second length) based on operating conditions. This allows the system to adapt between fixed and variable preamble configurations, resolving the contradiction between device simplicity and adaptability.
2Productivity
If DC balance encoded data is transmitted at high speed, then productivity is improved, but simultaneous switching noise increases
Solution Approach 1:
The patent changes the noise characteristics by adjusting preamble length parameters. By selecting between first and second preamble lengths based on noise conditions, the system can transmit at high speeds when noise is manageable while using longer preambles to reduce SSN when necessary, thus resolving the speed-noise tradeoff.
Solution Approach 2:
The patent applies preliminary action by using preambles of different lengths to prepare the transmission medium before actual data transmission. Longer preambles are used to establish stable signal conditions and reduce switching noise before high-speed data transmission begins, preventing noise issues rather than addressing them during transmission.
3Reliability
If current variations are reduced to minimize SSN, then reliability is improved, but transmission speed is limited
Solution Approach 1:
The patent dynamically adjusts preamble length based on current variation requirements. When reliability is the priority (high noise sensitivity), longer preambles are used to reduce current variations. When speed is prioritized (low noise sensitivity), shorter preambles are used, allowing faster transmission while maintaining acceptable reliability levels.
Data Source
AI summary
A data communication device or system includes a preamble unit and a data interface. The preamble unit generates or detects a first preamble having a first length for a first data line, and generates or detects a second preamble having a second length for a second data line. The first length is different from the second length, and data on the first and second data lines form parallel data. The data interface communicates a first data with the first preamble via the first data line and communicates a second data with the second preamble via the second data line. The respective length and/or respective pattern of each preamble are adjustable and/or programmable.