Embedded-Clock Data Transmission to Eliminate Clock-Line Skew
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Solution Overview
Problem
Point-to-point differential signaling (PPDS) requires a separate clock line, leading to increased complexity and cost in wiring, generates electromagnetic interference (EMI), and can result in errors due to skew between data and clock signals.
Innovation Solution
A method and apparatus that transmit data bits with embedded periodic transitions, allowing the receiver to generate a reception clock signal from the data signal, eliminating the need for a separate clock line and reducing EMI by using a data line for both data and clock information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate clock line is used to transmit clock signal, then clock signal transmission is reliable, but wiring complexity and production cost increase
Solution Approach 1:
The patent combines clock signal transmission and data signal transmission into a single data line. The transmitter embeds clock information within the data signal by generating periodic transitions, and the receiver extracts this clock information to synchronize data sampling, thereby eliminating the need for a separate clock line and reducing wiring complexity while maintaining transmission reliability
Solution Approach 2:
The data line is designed to serve dual functions: transmitting data signals and conveying clock information. By encoding clock information within the data signal stream through periodic transitions, the same physical medium performs both data communication and clock synchronization roles, reducing the overall number of required signal lines
2Reliability
If a separate clock line is used, then clock signal can be transmitted, but electromagnetic interference (EMI) components increase
Solution Approach 1:
By merging clock signal transmission with data signal transmission on the same line, the patent eliminates the separate high-frequency clock line that generates EMI. The clock information is embedded within the data signal, so only the data line operates, significantly reducing electromagnetic interference components
Solution Approach 2:
The patent converts the potential harm of requiring a separate clock line (which generates EMI) into a benefit by embedding clock information within the data signal. This approach uses the data signal itself as the carrier for clock information, turning what would be a source of interference into a useful synchronization mechanism
3Adaptability or versatility
If separate data line and clock line are used, then data and clock signals can be transmitted independently, but skew errors occur during data sampling
Solution Approach 1:
The patent merges the transmission of data and clock signals into a single channel, ensuring that both signals traverse the same physical path. This eliminates skew errors that occur when data and clock signals travel through separate lines with different propagation characteristics, as they now experience identical timing and path variations
Solution Approach 2:
The data signal acts as an intermediary that carries both data information and clock synchronization information. By using the data signal itself as the medium for clock transmission, the patent ensures that clock and data are inherently synchronized, as they share the same transmission path and timing characteristics
Data Source
AI summary
Provided are an apparatus and method for transmitting and receiving data bits. The apparatus includes a transmitter configured to generate a transmission signal corresponding to the data bits and having a periodic transition, a data line configured to transmit the generated transmission signal, and a receiver configured to generate a reception clock signal from the periodic transition of the transmission signal (“reception signal”) transmitted through the data line, sample the reception signal according to the generated reception clock signal to recover the data bits. Accordingly, it is possible to transmit clock information without a clock line separate from the data line.