Data String Inversion Encoding for DC-Balanced High-Efficiency Links
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Solution Overview
Problem
Existing data transmission schemes between image sensors and DSPs, such as the 8b/10b, 64b/66b, and 64b/67b encoding schemes, suffer from reduced transmission efficiency and difficulties in maintaining DC-free conditions, leading to deteriorated run length and running disparity, which affect clock reproduction and transmission efficiency.
Innovation Solution
An encoding and decoding method that calculates and controls running disparity and run length by inverting data strings based on calculated disparities and adding flags to maintain DC balance, thereby enhancing transmission efficiency and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If 8b/10b encoding scheme is used, then DC-free condition is achieved, but transmission efficiency is reduced
Solution Approach 1:
The patent changes the encoding parameters by using 64b/66b or 64b/67b encoding instead of 8b/10b, achieving better transmission efficiency while maintaining DC-free condition through running disparity control. The encoding ratio is changed from 8b/10b (20% overhead) to 64b/66b (3.125% overhead) or 64b/67b (4.6875% overhead), significantly improving transmission efficiency.
2Productivity
If 64b/66b encoding scheme is used, then transmission efficiency is improved, but DC-free condition is not achieved
Solution Approach 1:
The patent introduces feedback control through running disparity calculation and inversion determination. The encoder calculates running disparity based on the data string and previous running disparity, then determines whether to invert the data string to maintain DC balance. This feedback mechanism ensures DC-free condition is achieved while maintaining the high transmission efficiency of 64b/66b encoding.
3Reliability
If 64b/67b encoding scheme is used, then DC-free condition is achieved, but run length is deteriorated
Solution Approach 1:
The patent makes the encoding dynamic by selectively inverting data strings based on running disparity calculation. Instead of a fixed encoding scheme, the encoder dynamically determines whether to invert each data string to control running disparity, thereby maintaining both DC-free condition and acceptable run length characteristics.
4Reliability
If data string inversion is performed to control running disparity, then DC-free condition is improved, but transmission accuracy may be affected
Solution Approach 1:
The patent uses a flag bit as an intermediary to indicate whether inversion has been performed. The flag bit serves as a mediator between the encoder and decoder, allowing the decoder to correctly reconstruct the original data by knowing whether inversion was applied. This maintains transmission accuracy while enabling running disparity control through selective inversion.
Data Source
AI summary
Encoding and decoding devices, methods and programs are disclosed. In one example, decoding is provided by dividing input data into data strings of N bits, the data strings including a first data string, calculating a running disparity for the data strings, determining whether the first data string is to be inverted based upon the calculated running disparity, setting a flag for the first data string to a first value when it is determined that the first data string is not to be inverted, and setting the flag for the first data string to a second value and inverting the first data string when it is determined that the first data string is to be inverted, and outputting the first data string. The technology is, for example, applicable to a device communicating in an SLVS-EC specification.