Clock Domain Data Transfer Using Validated Codewords
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Data correctness is not guaranteed when transferring information between different clock domains due to metastability issues, which can lead to data coherency loss and functional errors.
Innovation Solution
An electronic circuit with an encoding circuit in the source clock domain that encodes data into codewords and a reception circuit in the destination clock domain to decode and discard invalid codewords, ensuring data integrity by filtering out incorrect values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If data is transferred directly between different clock domains, then transfer speed is improved, but data correctness deteriorates due to metastability
Solution Approach 1:
The encoding circuit performs encoding on data before it is transferred across the clock domain boundary. This preliminary encoding ensures that even if metastability occurs during transfer, the encoded structure allows the receiving circuit to identify and discard invalid codewords, thereby maintaining data correctness while enabling direct fast transfer.
Solution Approach 2:
The encoding circuit and decoding circuit act as intermediaries that protect the data transfer process. The encoding circuit transforms data into codewords with specific properties, and the decoding circuit reconstructs or discards data based on validation, thereby mediating between the source and destination clock domains to ensure correctness without sacrificing transfer speed.
2Reliability
If encoding and decoding circuits are added to ensure data correctness, then data reliability is improved, but device complexity increases
Solution Approach 1:
The encoding circuit changes the parameters of the data by transforming it into codewords with specific structural properties. This parameter transformation enables the receiving circuit to easily validate and detect errors, achieving high reliability with relatively simple validation logic that checks codeword properties rather than complex error analysis.
3Reliability
If validation and discarding of invalid codewords is implemented, then data purity is improved, but processing time increases
Solution Approach 1:
The decoding circuit performs only the necessary validation actions to identify invalid codewords based on their encoded structure, rather than fully processing and analyzing each codeword's content. This partial validation approach ensures data purity by discarding invalid codewords while minimizing the time spent on verification, as the encoding structure enables quick validation decisions.
Data Source
AI summary
According to one embodiment, an electronic circuit is described comprising a first clock domain configured to operate according to a first clock signal, a second clock domain configured to operate according to a second clock signal different from the first clock signal, an encoding circuit, in the first clock domain, configured to encode data to be transmitted from the first clock domain to the second clock domain into codewords and configured to supply the codewords to an interface between the first clock domain and the second clock domain and a reception circuit, in the second clock domain, configured to receive data words from the interface, to decode valid codewords and to discard invalid codewords.