Transmitter Circuit Run-Length Control for Stable CDR
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Solution Overview
Problem
Existing data transmission in data processing devices incurs overhead due to the need for clock data recovery (CDR) stabilization and maximum run length maintenance, leading to inefficiencies in data transmission.
Innovation Solution
A transmitter circuit with a run length detector, modifier, and scrambler is employed to detect and modify data bits when the run length exceeds a threshold, inverting specific bits to maintain maximum run length and reduce overhead, while using a scrambler to generate scrambled data with reduced electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If overhead bits are added to maintain maximum run length and stabilize CDR, then clock data recovery stability is improved, but data transmission efficiency deteriorates due to increased overhead ratio
Solution Approach 1:
The transmitter circuit performs preliminary detection of run length in the data stream before transmission. When a potential maximum run length sequence is detected, the circuit proactively inserts transition catalyst data bits in advance to prevent the run length from exceeding the maximum threshold, thereby ensuring CDR stability without needing excessive overhead bits.
Solution Approach 2:
The invention dynamically adjusts the data transmission parameters by selectively inserting transition catalyst data bits only when and where needed based on the detected run length. This conditional parameter modification approach maintains CDR stability while minimizing the overall overhead ratio compared to adding fixed overhead bits to all data streams.
2Reliability
If transition catalyst data bits are inserted to maintain maximum run length, then CDR stability is improved, but overhead ratio increases reducing transmission efficiency
Solution Approach 1:
The transmitter circuit applies transition catalyst data bits locally only at specific positions in the data stream where run length constraints are violated or approaching violation. Rather than uniformly adding overhead to all data, the circuit identifies specific locations requiring transition catalyst insertion, thereby maintaining CDR stability with minimal overhead ratio.
3Manufacturing precision
If data bits are inverted to control run length, then maximum run length is maintained, but data integrity may be compromised without proper compensation
Solution Approach 1:
The transmitter circuit incorporates a feedback mechanism that monitors the run length of transmitted data and tracks any bit inversions performed. This feedback information is used to generate corresponding compensation data that is transmitted to the receiver, enabling the receiver to correctly interpret the inverted bits and maintain data integrity while achieving precise run length control.
Data Source
AI summary
The present disclosure provides transmitter circuits and display devices including the same. In some embodiments, the transmitter circuit includes a run length detector, a modifier, and a scrambler. The run length detector is configured to derive position information indicating a first input data related to a threshold run length from among a plurality of input data in a predetermined bit unit, when a run length of first scrambled data for the first input data meets or exceeds the threshold run length in the predetermined bit unit. The modifier is configured to generate modified input data by inverting at least one bit of the first input data based on the position information. The scrambler is configured to receive the modified input data from the modifier, and generate second scrambled data by scrambling the modified input data with scrambling information.