Scan Chain Operations Using Serializer-Deserializer Datapath
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Solution Overview
Problem
Existing scan chain testing methods in semiconductor memory devices are inefficient, relying on flip-flop chains and multiplexers, which can lead to defects in electronic systems, especially in critical applications like automotive and medical devices, due to the lack of a native datapath for bidirectional data transfer.
Innovation Solution
The use of a serializer/de-serializer coupled with a native datapath allows for efficient transfer of scan vectors and test responses between a memory array and a device under test, enabling more effective scan chain operations by utilizing a native datapath for bidirectional data transfer, thereby reducing the risk of manufacturing faults.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If flip-flop chains and multiplexers are used for scan chain testing, then the testing can be performed, but the testing efficiency is low and manufacturing faults may be missed
Solution Approach 1:
The patent introduces a serializer/deserializer as an intermediary component between the memory array and the device under test. The serializer converts parallel data from the memory array into serial scan vectors, and the deserializer converts serial scan test responses back into parallel data. This intermediary enables efficient bidirectional data transfer through the native datapath, resolving the contradiction by improving testing efficiency while maintaining fault detection capability through the use of dedicated scan chain interfaces rather than general-purpose multiplexers
Solution Approach 2:
The patent segments the data transfer function into two separate dedicated paths: one for transmitting scan vectors from memory to the device under test, and another for transmitting scan test responses from the device under test to memory. This segmentation through separate serializer and deserializer operations allows each path to be optimized for its specific function, improving overall testing efficiency and reliability compared to using shared multiplexer resources
2Productivity
If a native datapath is used for bidirectional data transfer, then data transfer efficiency improves, but the device complexity increases due to additional serializer/de-serializer components
Solution Approach 1:
The patent implements the serializer and deserializer within the existing memory controller, allowing these components to serve dual purposes: they enable efficient scan chain testing operations while also supporting normal memory read/write operations through the native datapath. This multi-functionality approach improves data transfer efficiency for both testing and operational modes without requiring completely separate dedicated hardware paths, thereby managing device complexity through resource sharing
Data Source
AI summary
A number of embodiments include an apparatus comprising a memory array including a first memory bank and a second memory bank and a serializer/de-serializer coupled to the first memory bank and the second memory bank. The serializer/de-serializer may be configured to receive a scan vector from the first memory bank, send the scan vector to a device under test, receive scan test responses from the device under test, and send the scan test responses to the second memory bank. Scan control logic may be coupled to the serializer/de-serializer and the device under test. The scan control logic may be configured to control operation of the serializer/de-serializer and send a scan chain control signal to the device under test, wherein the scan chain control signal is to initiate performance of a scan chain operation using the scan vector.